## Thursday, December 22, 2016

### Mechanics Semester Review

Here is a list of topics for our final, the second week back from winter break:

Basics:
Vector algebra - vector addition, multiplication (dot and cross products)
Derivatives - finding them; what does it mean graphically; instantaneous values
Define v = dx/dt; a = dv/dt
Antiderivatives - finding them; what does it mean graphically
Motion graphs

Kinematics:
Constant acceleration equations, how to use them in a variety of problems
Free fall
Relative motion (e.g. boat going across a river)
Projectiles

Newton's laws:
Know them by number; conceptually what do they mean? Examples.
Equilibrium, balancing forces in multiple dimensions
Applications of Fnet = ma, all types
Tension, friction, on inclines (gravity triangle), springs
Systems problems, such as multiple blocks tied together
Circular motion, how to set up mv^2/R in problems; horizontal vs vertical problems
NON-constant forces and accelerations
Air friction, f = -kv; derivation of v(t); chain rule
Gravity - Newton's law of universal gravitation; Einstein's thoughts on warped space-time
Orbital motion - orbital speed, Kepler's laws; Binary orbits

Energy:
Conservation law
Different types, conversions of energy
Work redefined as an integral; work is the amount of energy transferred between objects
Using work and conservation to solve a variety of problems, especially with speeds and non-constant forces
Potential energies (gravity, springs)
How to do gravity the right way with energy, U = -GMm/r; what does - sign mean?
Potential wells - U-x graph vs F-x graph; positive force vs negative force
Gradient, F = - dU/dx; what this means
Power
Special relativity implications, Einstein's energy equation

Resources:
Videos on most of the topics above. For practice multiple choice, the SAT II site has notes, sample questions, and explanations on all these topics. There is a Learn AP Physics C site, with practice questions. We have our AP Exams folder (but you must be logged in only on your eths202.org account).  Note there is a multiple choice folder, with hundreds of practice questions. There are review sets in each of our unit folders. Read up on any topic and check out dozens of worked examples in Chapter 1-7, which is what we have covered so far. You have your old quizzams and solutions, homework sets, and labs.

## Sunday, December 18, 2016

### EM Semester Review

The main topics are listed below. Keep in mind this is covered in chapters 21-26. There are numerous worked examples and odd problems we can try, along with chapter review pages. There are videos on just about every topic. There are AP Free Response Problems and Solutions  (including a multiple choice folder); be sure to be logged in with your eths202 account for access. There are review sets in each topic folder on the school web site. There are practice problems and notes on the SAT II website. There is practice materials at the Learn AP Physics C site. Get into a study group. Come in for AM Support or lunch periods. Review old quizzams, HW sets. Review the essential questions you've received for each unit, and the objectives file. Review the equation sheet. Lab questions and concepts are fair game.

Topics
Electrostatics
• Properties of charge
• How do you charge objects? Induction vs conduction
• E-field and Potential for point charges
• F = qE and U = qV
• Work done when charges move around
• Energy conservation to find speeds
• Projectile example
• Equipotentials
• Non-gauss examples, integrals
• Sticks, rings, partial rings

Gauss's Law
• What does it define?
• Why does only 'charge inside' matter?
• Why only the three shapes that we use?
• Thin shells
• Materials: what are physical differences that make them have different properties? Band theory
• Conductors
• Nonconductors, uniform density
• Nonconudctors, NON-uniform density
• Combinations of materials in layers
• Finding electric potential for layers

Circuits
• Conceptually how do we setup currents in wires?
• What is resistance? What does it depend on?
• What is current? How would you find charge?
• What is power? How would you find heat energy from resistors?
• Series vs parallel
• Resistance
• Capacitance
• Conceptually what is same, different
• How to find current in each resistor
• Ohm's law, Kirchhoff's 2 rules
• Multi-loop
• Capacitor only circuits
• How to find charge on each
• RC circuits, series
• Conceptually what is happening?
• Can you derive q(t), i(t)?
• Charging
• Discharging

## Wednesday, December 14, 2016

### Videos for Dec. 14

Periods 1-2, 5-6, 8-9:

Check out a video on dielectric materials in capacitors. This will outline how to do the homework set for today. Then, check out the analysis/derivation of a RC circuit when the capacitor is charging. After these, the classes can check the solutions to the last test (in our Basic Circuits folder). You can then try to complete the HW set on dielectrics before leaving.

Period 3:

Check out a video on the conservation of momentum, and take detailed notes on this example. You'll need it to try a couple initial problems.
After the video, please get your energy quiz, as well as the solutions. You and 1-2 partners can go over these. Where relevant, do corrections on your quiz, and keep track of anything that does not make sense to you. When you get through the quiz, take a look at the momentum packet, and try questions #1, 4, and 5 on pages 2 and 3. Use your notes from videos, as well as the front page notes, and talk through these with partners. I will collect and check these tomorrow.

## Tuesday, December 13, 2016

### Try the Moody's December Math Challenge: Resistor circuits

Moody's, the huge financial firm in NYC, also sponsors the Mega Math Challenge for math modeling. In addition, they put out math challenges each month. The December challenge is one any one of the seniors should be able to do, fairly easily, since they are series and parallel resistor circuits! If you want to spend a few minutes and do these resistor circuits, you can get your solutions to DocV before winter break, and I can send them in. If you have correct solutions, you are eligible for a name drawing for \$25 Visa gift cards.

## Monday, December 12, 2016

### For New Units

Seniors, periods 1-2, 5-6, 8-9:

We will be starting capacitors and how these behave in circuits. Turns out plain capacitor circuits will hopefully look a lot like resistor circuits, as far as how we analyze them. We will still have Kirchhoff's rules. Ohm's law for capacitors will be Q = CV, since this is what capacitors do - they store charge in circuits.

Watch and take detailed notes on two videos.
Take a look at a video for finding total capacitance in series and parallel. The new unit that measures capacitance is called a farad, F, after Michael Faraday.
Then, check out a video on how to find stored charge on capacitors (this is like finding currents flowing through resistors). Note that capacitors in series have the same charge, and in parallel the same voltage.

Period 3:
We are starting momentum. This is a word you have all heard, but now we will be defining it and using it to help us understand collisions of all types.

Watch and take notes on two videos. One is an introduction to momentum.  The second is defining what impulse, or a change in momentum, is for objects when there is a collision.

## Wednesday, December 7, 2016

### Relativity and Energy: How E = mc^2 leads to numerous other features of Nature!

In my classes, when we are going through the usual classical physics portions of energy and work, I also throw in a couple days of modern theories of energy, including special relativity and some basic quantum mechanical ideas. After we see one way of deriving E = mc^2, and Einstein's energy equation in special relativity, I want to make a point that this is a truly large breakthrough in our thinking of the physical world. I like to use E = mc^2 as a stepping stone to better understand the following:
The discovery of E = mc2 basically sets up the discovery of quantum  mechanics, and the weirdness we see with particles.
Energy = matter, is effectively what this tells us.

These are two forms of the same stuff, like steam (energy) and ice (matter)  are two forms of the same H2O molecule.

Whatever properties energy (waves) can have, then matter (particles)  has those properties.
Whatever properties matter (particles) can have, then energy (waves)  has those properties.

Examples:
If waves have wavelengths, then so must particles
If particles have momentum, then so must waves (light/photons)
If matter is affected by gravity, then so must waves (light/photons)

This equation also re-defines conservation of mass and conservation of energy. In nuclear reactions, conservation of mass is violated, since products weigh less than reactants.
Conservation of mass-energy is now more correct!

• This equation changed the course of history, as we entered the age of nuclear power and weapons.
• It allows us to understand how stars form and 'burn,' and their life cycles
• It allows us to understand how heavier elements are formed through thermonuclear fusion (nucleosynthesis; we are made of star dust!!)
• It allows us to understand how the universe can form from a burst of pure energy (Big Bang), as we have phase transitions from energy to matter or vice versa.
• The unification of space and time allows us to understand what causes gravity (warps in space-time)
• It allows us to understand how to make particle accelerators and explore the basic question, "What are we made of?"
• It led to the prediction of antimatter
• It allows us to think in terms of multiple dimensions, giving rise to things like string theories
• It allows us to begin to understand radioactive processes, and nuclear physics
• The theory of photons allowed Einstein to understand photoelectricity (solar energy), for which he won the Nobel Prize
• This also helped lead to his discovery of 'stimulated emission,' the process that makes lasers possible

• It predicts 'matter waves' or the wave-particle duality, which is the heart and soul of quantum mechanics

## Sunday, December 4, 2016

Here are some quick links for our energy unit.

Energy conservation and finding speeds
Gravitational energy 'the right' way
Potential wells
Finding tension for a pendulum (need energy to do so)
Springs and energy
Special relativity: one way to get the E = mc^2 result
Special relativity: energy equation to particle-wave duality

And if interested, how a nuclear power plant works. This video does a good job of showing the gist of the different parts of the plant facility.

## Wednesday, November 16, 2016

### Resistor Circuit Analysis

Check out the video about how to analyze resistor circuits, with both series and parallel sets in the same circuit. Take notes on this, and try the first three examples in the packet. Then you and your lab partners can work on completing the two labs. Also, check out a video on multi-loop circuits, and also a video on band theory (focus on how and why the bands form in the first place), which may help with your conceptual understanding in here as well as in chemistry.

## Thursday, November 10, 2016

### Juniors - Consider Summer Science Program (SSP)

For Juniors: One of the very best and intense summer programs is the Summer Science program.  This is a chance to get into some upper-level physics and astrophysics, learn some coding, and get into projects of tracking and simulating asteroid orbits, and more! We have had a few get into this program and they loved it, including one current senior who is willing to chat about it to anyone who's interested. Check it out and apply!

## Monday, November 7, 2016

### CT-STEM site and assessments for 3 Chem-Phys

Go to the NU CT-STEM site http://ct-stem.northwestern.edu/ and log in. This is from that email you should have received a week or two ago. CT-STEM stands for Computational Thinking in STEM, and we are participating in this program as new curricula are being developed and piloted for widespread use in the next few years, as much of the country has adopted the Next Generation Science Standards. You should have two assigned tasks, one a survey and one a pre-program assessment. These are just done online, and should not take a huge amount of time. Your scores will be used as part of a larger study at NU about the effectiveness of the activities we will do throughout the year, and your names are anonymous in the study. Thanks!

## Monday, October 31, 2016

### Classes on Halloween

Periods 1-2, 8-9

The students should break into groups of 3-4 and try the 8 circular motion questions, and get it turned in. Once this is completed, watch and take detailed notes on videos for the two types of air friction cases we do. The first is when air friction is the only force acting on an object, like a hockey puck. The second is when there is a second force acting on an object with air friction, such as on a skydiver. Note that something that comes into play for teh skydiver type problem is the chain rule. Check out a video for chain rule if this is a new concept for you.

Students should then be sure to have the pendulum mini-lab completed and shared with Doc V at vondracekm@eths202.org. We will go through the priorities Tuesday.

Period 3

Students will get there tests back with solutions. They should review and make corrections together, in small groups of 3 or 4. They should talk through and make sure everyone in the group is OK with each answer/solution.

Then, students should watch and take notes on two videos. One is an introduction to circular motion, and the idea that a force is needed to allow a car to make a turn. And then a second that introduces the concept of centripetal force - a force pointing inwards, towards the center of the circle the object is moving around. We will start to make sense of this tomorrow, using pendulums.

## Sunday, October 30, 2016

### Article on Hunting for Planet 9 - a large 'Ghost planet' - using laws of gravity in simulations

There is a Scientific American article on the hunt for planet 9, that presumed planet way the heck out there is a 10,000 year-plus orbit. It is presumed because of computer simulations that suggest there must be something out there to account for the motions of other objects within the solar system. And these simulations are based on the laws of gravity, which we are studying right now to understand at least the basics of orbits. Scientists have narrowed where to look for the planet by half, so the hope is to have visual contact in the next few years to confirm what the simulations predict. By the way, it is predicted to be about 20 times the mass of the earth, and have an orbital radius that averages between 380 and 980 AU (1 AU is the radius of earth's orbit, or 93 million miles). If you are participating in the research club, then the programming skills you are acquiring could be used to do such simulations in the future! All of this stuff fits together at some point!  :-)

## Thursday, October 13, 2016

### For classes today

Periods 1-2, 5-6, 8-9:

First, try to reach consensus on the two problems from Tuesday, with non-uniform charge densities. Focus on the setups, as you talk with each other and compare what you had. Feel free to bring up the AP solutions if necessary, either on the front computer or your chromebooks or phones..

We are moving on into NON-Gaussian problems, where we will need to find the E-fields and potentials for objects that are not spherical, flat, or 'really long.' Actual wires and sticks actually do have ends, so how do we handle reality? Watch a video and take notes on how to do this for sticks, as well as a curved stick/partial ring. There is a third on finding potentials for sticks. These involve integrals, as we try to sum up the E-field components and potentials from each point charge on the object.

In our packet, you can begin trying the problems on pages 6 and 7 in small groups.

Period 3:

You should watch and take notes on a video about Newton's law of gravity, which has an example of how to use it, as well as a second video on how to use Newton's laws to figure out how strong gravity is and the acceleration of gravity at different distances above the earth.

Based on these, you can get into small groups and go through the homework problems from Tuesday, helping each other figure out how to do them (similar to examples in the videos), and reach consensus on your answers. We will extend on these ideas tomorrow and get into figuring out how fast satellites need to travel to stay in orbit, as well as how fast we are moving around the Sun right now!

## Sunday, October 9, 2016

### Fundraiser for Malawi Schools - Planting Crops to Fight Famine!

For those interested in learning more about the situation in Malawi, Africa, and the drought and famine that are presently taking place for millions of people, you need to be logged in with your eths202.org account and can click here for more information. We are trying to get cash donations so we may get money to teachers on the ground, which they will use to begin planting crops specifically for the schools. Students will learn about agriculture in this type of environment, so they may develop the skills necessary for the subsistence farms which are common to this part of the world (where there is also severe poverty). Thank you for your interest, and any donation can be brought to Doc V in room H322!! If we average just \$1 per person in ETHS, we could help fund crops for four schools!

## Wednesday, October 5, 2016

### Next set of material in E&M

We will be finishing off Gauss's law, with non-uniform charge densities. Then we will begin looking at how to find potential for shells of charge, and this will move into techniques for finding fields and potentials for NON-Gaussian shapes, such as sticks with ends and partial rings of charge, using integration.

## Monday, October 3, 2016

### Nobel Prize week!!

The Nobel Prize for 2016 for Physics went to three professors who, in the 1970s and 1980s laid the theoretical groundwork and topological predictions of strange phases of matter. Things like superfluids, superconductors, single-atomic layered materials, thin magnetic films, and so on, were predicted, and over the past couple decades others have developed the technologies and experimental methods for actually showing these weird states of matter can exist. Generally they only exist in the lab, and not naturally, such as superconductors and superfluids, simply because they require such low temperatures. Scientists and engineers are just learning how to apply these things to next-generation technologies, which some of you may very well be involved in!

The Nobel Prize for 2016 for Chemistry went to three professors, including Fraser Stoddart of Northwestern, They were some of teh first scientists to work on and actually develop first generation nanomachines. These are machines with moving parts and energy sources that are of molecular size scales! Many say that these are like the first electric motors of the mid-1800s, and the applications of the nanomachine era are waiting to be developed, leading to an entirely new industry and level of technology that has never existed. Your generation will develop this new sector of industry and technology!

The Nobel Prize for 2016, for Medicine and Physiology, was awarded today to the Japanese doctor Yoshinori Ohsumi. He was responsible for discovering how cell's can degrade and recycle cellular components, which is a process all cells carry out. It may have huge implications on a variety of diseases, such as cancer, that are based around cellular processes that have gone awry. This process is now called autophagy.

## Friday, September 30, 2016

### Possibilities for research in an NU lab - some quantum implications!

Especially juniors, let Doc V know if you have any interest in the lab of Prof. Chandrasekhar. There are some research options that will be available!!

## Thursday, September 29, 2016

### For Classes

Hi everyone, my apologies for having to get home to get a sick kid to the doctor.

Periods 1-2, 8-9:

The quizzam is tomorrow, so you have a chance to do review sets. One is on the school website. Go to the Newton's laws folder, and check out the Review Set. Solutions and explanations are all in the file. There is also a good site with practice questions at Learn AP Physics C.  Click on Newton's laws for practice questions and solutions.

If you need to do any last minute finishing touches on the lab report, you can do that. Share labs with vondracekm@eths202.org. Work together to make sure you are good with the HW sets, which are all collected tomorrow.

Period 3:

Watch the launch scenes from the movie 'Apollo 13.' Use the video guide the substitute gives you as you watch, and think of things in terms of Newton's laws that we are studying. Think about what forces are involved, what the astronauts would be feeling at different stages of launch, and the resulting motion of the rocket.

## Monday, September 26, 2016

### Full-tuition scholarship opportunity for women in STEM

Senior ladies, if you are going to study anything in STEM in college, you may want to check out the Science Ambassador Scholarship program, where one woman will win a full-tuition scholarship to college! The first step is produce a 3-minute video lecture on any science topic you are passionate about, and submit it. Check it out!

## Thursday, September 22, 2016

### Responses to Science Issues by Presidential Candidates

If you are interested in the responses to 20 science related issues from Hillary Clinton, Donald Trump, and Jill Stein, check out this Scientific American article. Gary Johnson did not respond.

## Sunday, September 18, 2016

### Classes for Monday - Wednesday, Sept. 19-21

While I am in NYC, the substitute has detailed work for each day. Some of this will require watching a video or two. Take notes on these, and keep track of any questions, so we can re-group on Thursday.

Period 3:
On Monday, check out two videos. One is on Newton's 2nd law of motion (F = ma). The second video is on Newton's 3rd law of motion (action-reaction). You should be remembering these laws by number. Take notes on these, and we will be using them quite a bit throughout the year - since forces are around us all the time, our entire lives, these basic laws will help us understand a whole bunch of things!!

Note that Wednesday is a C-day, and juniors (most of teh class) will be in assigned rooks for PSAT stuff.

Periods 1-2 and 8-9:
On Tuesday, watch and take notes on a video for finding acceleration and tension in systems of objects.

On Wednesday, watch and take notes on two videos for integration (anti-derivatives) and circular motion examples (centripetal force, mv^2/R).

Thanks, and we will be making sense of these when I am back Thursday!!  :-)

## Wednesday, September 14, 2016

### Gauss's law for conductors and NON-conductors

In 4 Chem-Phys we are trying to understand the differences between conducting objects that have a net charge and NON-conducting objects that have a net charge. Remember, what we are discussing is only for STATIC electricity.

Conductors/metals have those metallic bonds, where the delocalized electrons can move. If an E-field interacts with a conducting material, such as one of the shells we were talking about in class, then that shell can polarize. The consequence of the polarization and the behavior of conductors with static charge is that the net charge ends up on the outer surface. This also means that the E-field inside the conducting material is E = 0. Note that if the E-field is not 0 inside a conductor, then there would be an electric current, and not static electricity. The video for conductors is here.

NON-conductors/insulators do not have metallic bonds or a 'sea of free electrons,' which is why they do not conduct currents. But this means it is OK for any net charge to be spread throughout the volume of the material - it can't move, so it would still be static charge. According to Gauss's law, there will be an E-field inside the material. This is where we need to work with charge density, which is charge/volume. Our job using Gauss's law is the same as always: try to figure out what to put in for the charge inside any particular region of the system. The video for NON-conductors is here.

## Saturday, September 3, 2016

### "Zombie Genes" that turn on after death

Check out an article about "zombie genes," which have been discovered in various animals that have expired. These are genes that do not activate or do much of anything when the organism is alive, but instead become active after the organism dies. This may have important implications for something like organ transplants. Who would have thunk it?!

## Thursday, September 1, 2016

### Good example of how STEM works in this day and age - Collaborations for Power Grid Security

My alma mater, UIUC, just had some \$18 million dollars in grants given to it (the College of Engineering, that is) to develop the most robust platform for testing the security of the U.S. power grid. The U.S. is in the process of a long-term renovation of the decades-old power grid, which is outdated in terms of both technology and security, and developing the whole 'smart-grid' concept. This is one where engineers and power companies will have better data and faster responses to problems with the grid, where computers can automatically control where and how much power is being sent to different users on the grid based on demand and resources, better efficiency and cost control, better energy conservation, hooking up new energy sources to the grid (such as solar, wind, geothermal, bio-based sources, etc.), and increasing infrastructure to places where it does not presently exist so there can be expansions of wind farms and solar farms in the future. This is a HUGE project and will proceed for many years to come (making it a good time to be a civil, computer, environmental, or electrical engineer), but without a robust security system on the grid, it will always be vulnerable to attacks, especially via the Internet. This type of research is absolutely crucial for the U.S. future.

### Plans for September 1

I am really sorry for being out, but a fever and stomach issues are forcing me to go back home. Please do the following for today:

Periods 1-2, 8-9
The quizzam is still on for tomorrow, so today be sure to get into study groups and be sure the various homework sets are making sense. Homework sets are collected tomorrow. Be sure the lab is shared with me at vondracekm@eths202.org. You can try the practice problems the substitute teacher will pass out, and these and solutions are on my school site: go to the 3 Chem-Phys site and in the Foundations folder is the file called Review Set. Other resources include reviewing sections in the textbook, trying other odd problems and checking answers in the back, and trying and checking yourself with the worked examples in every section. We are doing stuff from chapters 1 and 2 primarily.

Quizzam main topics:
Derivatives of functions (no algebra required!), y = cxn
1-D motion problems with constant acceleration and non-constant acceleration
2-D motion: relative motion, projectiles
Motion graphs        Graphing data           Standard deviation, error bars

Period 3
We will hold off on your rankings of issues until tomorrow. Today, I want you to try getting data for our speed lab. You will get the lab sheet and some additional direction from the substitute teacher. The measurements you will need to make are for a marble rolling down a ramp and onto the table-top. You will need to select 5 different distances from the end of the ramp, and then for each distance do 4 time trials; you will be using the average time for each distance you select. Be sure to start the marble at the same height on the ramp every time you let it go, because you want to have the same speed on the table every single time. Keep track of all this with a data table you and your partners decide on. Ultimately we will be making a graph to determine the speed of the marble. Remember that speed = (distance)/(time), or v = d/t. We will get into the analysis tomorrow.

Thank you everyone, and let's make the most of it until tomorrow. Happy Thursday!    :-)

## Sunday, August 21, 2016

### Welcome Back for the 2016-17 School Year!!!

I hope you have all had a wonderful summer, with a chance to relax, re-charge, and get set for the 2016-17 school year!! I know we will have great phun as we pursue another year in physics. The 3 Chem-Phys classes will begin a focus on classical mechanics, with some number of other topics to enter into the discussion. The third period, first-year physics class will become the scientists as they help me how to figure out our world essentially from scratch! And the seniors in 4 Chem-Phys will have to put up with me a second year as we enter the crazy world of electricity and magnetism - some topics will attract attention, while others are bound to be totally repulsive to students...(that's all I got at the moment). All seniors will be busy with college apps and all that comes with that process, but hang in there, you will make it through, I promise.

Here's to a great year!! Never hesitate to come chat with me about anything, as I want each and every one of you to learn a lot and have a great time doing so. Thank you!  :-)

## Wednesday, August 17, 2016

### Hand written notes generally better for learning than typing on a computer

I've posted on this before, but it is important as ETHS and many other districts continue on the 1-to-1 technology path. Sometimes 'old school' is better than using technology for everything. For instance, more and moer studies are reaching the same conclusion that taking notes the old fashioned way, by writing, is better for learning for most people than typing notes out on your computer. There are several reasons for this, but it can generally be summed up that the more senses and the more time we can give our brains to process information, the better - the more synapses are created, making for better conceptual understanding and memory. Check out a Scientific American article on this topic.

## Sunday, August 14, 2016

### How elite sprinters go so fast

A second article relevant to the Olympics is how elite sprinters go so much faster than the average human. Check out the article and video at Scientific American, where measurements are made on a world class sprinter. It turns out the hit the ground much harder than the average person (and think about the 3rd law - if you hit something harder, it will hit you harder, and provide a larger acceleration). Cool!

### Physical exercise benefits cognition

In the spirit of the Olympics, a long-term study shows a significant cognitive benefit to those people who exercise regularly and maintain good physical fitness. Check out a summary article in Scientific American. The researchers admit that why this is true is not well understood, but some hypotheses are that the increased blood flow during exercise, which includes more oxygen to the brain, is a benefit to the brain and its cognitive power. A second possible reason is that during exercise, cells produce more mitochondria, which, if you remember your biology, is the energy plant of a cell. So even brain cells have more energy to use due to exercise. A third possibility is that increased heart rates increase neurogenesis, or the growth of more brain cells.

## Tuesday, August 9, 2016

### Wolfram Language Online

Check out Wolfram Language, which is a powerful, but 'simplified' way of programming. There is an online interactive book that will allow you to learn this way of programming, with numerous examples and exercises to try as you go. This looks very promising as I skim through it, so it may be the way to go if you want to learn a programming language...may be the easiest language yet, so let's find out!

Also can check out:
The Wolfram Programming Lab where you can open a notebook online, for free, and try Wolfram Language.
Mathematica Online if you want to check out what numerous colleges use for STEM coursework, research, and so on.

## Friday, August 5, 2016

### Israel showing how to do desalination on a massive scale

Just a few years ago, Israel was in its worst drought in some 900 years. Out of necessity, investments were made in desalination plants. Now, Israel has more clean, potable water than it needs! One 'trick' to get around bacteria that ere clogging the filter pores that captured larger salt molecules as water molecules passed through was to add in natural lava pieces that filter out bacteria prior to getting to the salt filters. Human ingenuity in action, as well as making use of natural solutions to modern problems. Check out an article here.

### The hope for a new particle fizzles with more data

Out at CERN, the highest energy machine in human history (yes, it unfortunately outdoes what we had at Fermilab by several times now), a hope for a new, unpredicted particle seen in some of the data last year, has statistically gone away as new data runs have been added. This is a good example of how science works, where one does not just take some new little spike in a data set as a new discovery and, in this case, a sign for new physics beyond the Standard Model (which is the theory that explains and describes what we know about particles, matter, and forces).

Each branch of science has standards that must be met before one can claim a discovery, and in particle physics it is a '5-sigma rule' where there must be, effectively, small enough uncertainties that will allow a 1 in 3.5 million chance that the discovery is something other than what we think it is, i.e. a miniscule chance that the data are showing a fluke. I know about this firsthand when, back in grad school and on an experiment searching for the top quark, we had a mass peak but, due to the statistics of the data set, we only were in the 2 sigma or so range that this was the top quark. We felt pretty confident that it really was, since there were multiple checks and re-checks of the detector, software, and data quality, but we could not claim discovery - we instead published a paper on the 'evidence for the top quark.' It took another year of millions more collisions before we reached the 5-sigma standard, and then claimed discovery. I am glad to see these scientists are doing things the right way, and upon further review and new data, found out the peak seen earlier is apparently a statistical fluctuation.

See a Scientific American article here.

## Monday, July 11, 2016

### Examples of DIShonest Science Research

Scientists are human, and sometimes humans are dishonest and try to cheat. There are, unfortunately, cases where scientists created data, ignored results that did not fit with their ideas or models, rushed results in order to publish quickly, and so on. A discussion on these can be found on the NSTA Blog.

## Wednesday, June 8, 2016

### Creativity - Using Elephant seals to dive under Antarctica and get Data about why the ice shelf is melting!

Because the ability for humans to dive under the Antarctic ice shelf does not really exist, scientists have put small sensors on elephant seals to measure water temperature, depth, and salinity. With tens of thousands of dives and data sets, they have determined one reason why the ice shelf has been melting (from bottom up) so quickly - there is a warmer pocket of water that gets mixed into the colder water, raising the temperature above the melting point. This mixing is part of an underwater cyclone! Fascinating results from a truly creative way of collecting data. Check out the Washington Post article.

## Wednesday, June 1, 2016

### A 'Thank you' from Australia!

Our friends from down under, in Mr. Christian Williams's 1/2 class, sent us a thank you video, which is the cutest thing ever!! Check it out!

## Thursday, May 26, 2016

### Case Study: Re-focus Schools to More Creativity

There is a really interesting article and news report on Effingham High School, which is in mid-Illinois, and how student creativity and global citizenry is a school-wide focus. This change in school culture has been evolving for the past decade or more, largely due to the efforts of my friend and fellow Varkey Teacher Ambassador (and top 10 finalist for the 2016 Global Teacher Prize) Joe Fatheree. Check it out - I am in agreement with this approach!

## Tuesday, May 24, 2016

### Big Data - Are you ready for it???

This is a really good article and video from Northwestern (a few friends in the video, who have been leading the charge on this for a number of years already!). Big data is already here, and for those of you who go into academia, you will be learning how to handle this and work with it in all types of research! Check it out!

## Sunday, May 22, 2016

### A new Chem-Phys video! How does it compare to the classic 'Chem-Phys is so hot'?!

Thanks for the following video: Ryan, Evan, and Kobi! Class of 2016!

## Friday, May 20, 2016

### Good introductions to Quantum Mechanics

The two video links below allow you to watch the development of early quantum theory, with names like Planck, Einstein, Rutherford and Bohr being presented. These are well done and hopefully shed some light on the subject!

Part 1:

Part 2:

## Tuesday, May 17, 2016

### Some potions, fire, and bangs - science in Evanston!

Hello, class 1/2 at St. Michael's!! We are here in Evanston, Illinois, USA, and we have done some science experiments for you. Everything from flaming chemicals to slime to some small bangs...we hope you enjoy it, and as you learn more science you will begin to figure out how these work! Keep asking questions, which is what scientists have to do, and never stop being curious about how things work!

## Monday, May 16, 2016

### New technique for discovering dark, dwarf galaxies

At my alma mater, UIUC, researchers have discovered a dwarf galaxy some 4 billion light years away from earth, which emits little, if any, visible light, by using gravitational lensing of a even more distant galaxy that is 'behind' the dwarf galaxy. This technique, they think, will allow for more dwarf galaxy discoveries, and also allow astronomers to test dark matter models, which these galaxies should fall under since they are not in the visible part of the spectrum. dark matter is, of course, one of THE open questions in all of physics, and perhaps this new technique can shed some new light on the topic. (ouch, I know this pun is painful..I'm just not bright enough to come up with any others...)

### Potions and going back in time to see how science started!!

This is a video put together in response to some questions from Gus at St. Michael's! It shows a bit about potions, and a little on two early scientists, Aristotle and Galileo. Galileo especially helped start modern science because of his use of observations and experiments. Prior to Galileo, Aristotle (from ancient Greece) had made use of philosophy to think about how the world works...this is not entirely how modern science works, but it began a way of thinking about Nature and how it works!

## Friday, May 13, 2016

### Thinking about Time and Time Machines...

Here are some thoughts from Shanti, Claire and Atticus, about time machines. Unfortunately, modern science don't think time travel is possible, but there is a neat way of thinking about seeing things in the past! Check out this video and see what we mean!

We hope all is great 'down under!'

### Learning some science with Evanston seniors!

This goes out to all the kids in Mr. Williams's classes in Australia, from us in Evanston, Illinois, USA!! Thank you for your letters and questions. We have some fun science activities and experiments you might be able to try! From Nick, Harry, Nathan, and Mitchell!

### Making video games with Scratch - for St. Michael's Primary!!

Hello, from Evanston, Illinois, USA! Murielle, a high school senior, liked the letters that asked about computers and games, so she wrote her own game using something called Scratch! Check out Murielle's game here. You can even see what her 'code' looks like...this is the program that makes the game work. Scratch is something that uses puzzle pieces to learn how to make programs, so it is something you can try! It is free and on the Internet, at https://scratch.mit.edu/.

### Some cool Science for St. Michael's 1/2 class!

G'day! From Evanston, Illinois, in the USA. We are in the twelfth grade and wanted to show you some cool science, some of which you might want to try! Thank you for sending the wonderful cards with your questions, especially Gus!
- From Nora, Emma, Julia and Christian (not your teacher!)

## Tuesday, May 10, 2016

### Richard and Logan's "Robot" to St. Michael's Primary School

Hello Inquiring Students,

Hopefully you all enjoyed the clip of the Logan Bot 3000. What we did today in class is very similar to what professionals do when they make robots that are told what to do by computers. Computers give robots and other machinery very specific directions in computer codes. Such codes come in many different languages as do the ones us humans use to speak. However coding languages do not have sentences, they look like this:

If anyone of you is interested in learning how to make robots like the ones in the videos below, I suggest you take computer science (CS) classes. In a CS class you will learn how to construct code in different languages the same way people make Legos and puzzles. Have fun with the rest of your education and never stop asking questions!

## Friday, April 29, 2016

### New York Times article about Achievement Gaps: Mentions Evanston

At ETHS, our top district challenge is to chip away and eventually eliminate the historic '2 schools in one' reality, meaning that our white students achieve at some of the highest possible levels, and our students of color are, on average, performing significantly lower. Achievement gaps are not unique to Evansotn by any means, but are instead a national problem. I have been lucky to help start and work with Project Excite over the past 15 years, where we work with 3rd grade students and then support them with enrichment classes, family support, and peer role models up through middle school. Data on the old ISAT and EXPLORE tests show that the achievement gap is eliminated in math and reading over that period of time. So there are things that can be done that work on preparation.

A new study on the gap issue has been summarized in the New York Times, which has some interesting interactive graphics that allow the reader to see the gaps for hundreds of districts nationwide for 6th grade students. Evanston DIst. 65 is in this sample. Evanston was noted in the article as a district with high median income (one of the wealthier areas with a diverse population), but with a large gap. While over 40% of Evanston's students are on free or reduced lunch (i.e. low income), the median income is over \$90,000, so we have wealthy students standing side by side with students from poor households. Most of the low income students are minority. It has been no secret for some time that socioeconomic status is the one consistent indicator of academic performance in school.

One thing we know from Excite is that there is no quick fix to achievement gaps. It is a multi-year solution. Another piece of this is common sense, if you start working on the problems at earlier ages, you are more likely to make a difference. We know it is an incredibly complex issue, part cultural, part economic, part environment, part mindset, part peer pressure, part role model, part family support, part curriculum, and so on. Issues are different for each individual student and family.

Let's keep trying, before another generation of students finds itself locked into the same achievement and performance gaps as years' past.

## Tuesday, April 19, 2016

### Induction stoves - some examples

EM Induction has many uses and applications out in the world, and an induction stove is another good example that is not as well known as others. Check out this short video with some good examples of what one can do with such a stove. Remember, it is an AC current underneath the surface, and for NON-conductors this is no big deal...for conductors, such as a metal pot, currents are induced that produce heat due to the electrical resistance. This is an example of emf = A dB/dt (note that this also means circulating electric fields are being generated/induced in the pot, creating the electric currents).

## Friday, April 15, 2016

### Video links for Simple Harmonic Motion

As a short cut, here are some quick links for SHM videos:

Basic derivation of sine and cosine solutions
How to construct a solution with phase angle
The simple pendulum and small-angle approximation
A stick oscillating due to spring and small-angle approximation.

For kicks, if you want to see where a quantum number comes from, we can use SHM of an electron and Schrodinger equation . This is kind of cool!

## Wednesday, April 13, 2016

### For Thursday: Intro to SHM, and Inductor Circuits

Periods 1-2, 6-7, and 8-9:

Classes can start off in small groups and go through solutions to any of the problems the past couple days. Decide which of the old AP problems you would like to pull up from the online folder of solutions. After this, we will be starting simple harmonic motion, our last topic. There are some connections with rotations, which we will begin identifying Friday, but for today we will focus on collecting some data with oscillating springs. Get the lab sheet from the substitute teacher, get into lab groups of no more than 4, and you can use the equipment that is set up. If your group has time to spare, you can begin the analysis (focus on graphs), or work on problem sets if there are parts that do not make sense.

Periods 3-4:

Please feel free to bring up any solutions to the old AP problems we've had the past couple days, and in small groups see if things are making any sense. Keep track of questions we can address on Friday. Then, check out two videos on our last circuit component, the inductor. This is basically a small solenoid you put in circuits. These will also be very similar to RC circuits as far as the math is concerned. Get the new packet from the substitute teacher, which we will be using.
The first video is when a resistor and inductor are in series with the battery.
The second is when a resistor and inductor are in parallel with each other.

After the videos, try AP Probs 2005, 2008 on pages 2 and 4 of the inductor packet.

## Monday, April 11, 2016

### For Wednesday: Angular Momentum and Faraday's law

Periods 1-2, 6-7, 8-9:

Share labs with vondracekm@eths202.org.

The last type of collision involving angular momentum is the type where BOTH linear and angular momentum are conserved. This would be something like hitting a stick that lies on a tabletop. If there was no friction, then there would be no net force adn no net torque on the stick once it is moving, and therefore BOTH types of momentum would be conserved. The stick would rotate about the center of mass, and the center of mass is the one point of the stick that would move linearly. Check out the video on this type of collision and motion.

If anyone needs to review other examples of collisions and angular momentum: There are a number of instances where collisions occur with objects that rotate. Putting a golf ball is basically a rotating stick colliding with the ball. A person stepping off a playground merry go round disk, or running and then jumping on a disk, is like an 'explosion' or inelastic collision, respectively.
Or throwing gum or a dart at a ball or tire will cause rotations after they stick together. And many more (often goofy!) examples can be dreamed up.

These tend to look like (mv_i)rsin(beta 1) + (I_i)(w_i)  =  (mv_f)rsin(beta 2) + (I_i)(w_i). Note that if things stick together, we will need to add moments of inertia together.
Video similar to putting a golf ball
Video examples of collisions with angular momentum

HW due Friday: AP Probs (1981, 1998) on pages 4 and 9. *Work together and use SP solutions if necessary to check yourselves. Also talk through any other HW problems in your groups that you have questions on.

Periods 3-4:
We are working our way through EM induction and Faraday's law, and presently the focus is on the type where induced voltage = emf = -A dB/dt. The main concept we want to understand here is that the physical reason why a current turns on is not because of magnetic forces, but instead because when a B-field changes, an electric field turns on...and this E-field circulates! This is very different from a radial E-field that we are used to in electrostatics. The circulating E-field circulates in our loops of wire, and it is the electric force, F = qE, that pushes charges in the wire loops! Weird!

So EM induction basically says:
If there is a dE/dt, a circulating B-field turns on, AND if there is a dB/dt, a circulating E-field turns on.

Check out and take notes on two videos for this type of process, with circulating E-fields. We know how to handle this because we have done Ampere's law for circulating B-fields already - it is a path integral. The first video is a stranger example of flux and how to find it, along with dB/dt, and the second video is about finding the circulating E-field that turns on in these cases.

There will be a new post for Thursday, since Doc V and a couple seniors will be in Champaign for WYSE state finals.

HW due Friday: AP Probs (2010, 1978) on pages 4 and 5. *There are worked examples in the packet, as well. Feel free to work together and check solutions online for any of this.

## Sunday, April 10, 2016

### My Dubai experience and the Global Teacher Prize

A couple years ago, Mr. Sunny Varkey, who lives in the United Arab Emirates, learned of a truly disturbing statistic. According to a survey and study by UNESCO, which is the education branch of the United Nations, there are presently some 500,000,000 (yes, half a billion) children who attend underperforming and failing schools. And yes, some of these are in the U.S.; just look at some Chicago high schools where there are still dropout rates of 50% and graduates read at elementary and middle school levels.

The Varkey family wanted to do something about this, and has been using a good portion of the family fortune to create the Varkey Foundation, which has its headquarters in the United Kingdom. The Varkey GEMS group has created and runs some 250 schools worldwide. But Mr. Varkey also knows that to make the biggest difference in alleviating poor schools and improve the education and learning opportunities for all children worldwide, we need to improve the status and level of expertise of the single most important part of the education equation, and that is teachers.

No progress will be made in education if we do not have great teachers. But to do this on a massive, global scale, how the public and how policymakers look at teachers and the profession, which is not always stellar, must improve. It is well known that teaching is often not respected as a profession the way doctors and lawyers and engineers are. Pay is among the lowest of all professions. Top students typically do not aspire to be teachers (likely because of the lack of status and income). This is true not only in the U.S., but in nearly all countries around the world. Our motto is simply, "Teachers Matter!!!"

In 2014, the Foundation sponsored a first of its kind program to begin raising the status level for the teaching profession, the Global Teacher Prize. Mr. Varkey announced he wanted to create the equivalent of the Nobel Prize for teaching and education - for the past two years, the top  50 teacher finalists were announced, and from those two groups there has been a \$1 million winner of the Global Teaching Prize, and nominations have come in for thousands of teachers from over 160 countries.

I was unbelievably fortunate to have been in the inaugural class of finalists in 2015, from which Nancie Atwell of Maine was the first winner of the prize (she was awarded the prize by the Crown Prince of the UAE and President Bill Clinton). We represent 26 nations. The 50 of us have been named the first group of Varkey Teacher Ambassadors (VTA), and in March of 2016, the first VTA Leadership Summit was held in Dubai. We had two days to meet face to face, and begin a discussion of what we want this group and network to do. Those of us who could make it were joined by many of the teachers from the second cohort of VTAs from 2016 (collectively representing 36 nations). The culminating event at the conference was naming this year's winner of the Prize, Hanan al Hroub of Palestine. Her name was announced via video by the Pope.

I encourage anyone who reads this to nominate a great teacher or colleague (nominations open in May). While there are countless great teachers in classrooms around the world, especially think of those teachers who also excel outside the classroom, taking part in training other teachers, publishing articles or videos to broad audiences, run their own schools, create programs or projects that have effects on a broader scale, have their students involved with sister schools (especially internationally) and do service projects, develop new teaching techniques/methods, are politically active and making change in education policy, and so on. Honestly, it helps if the teachers have already received recognition in other capacities and have 'a reputation,' as well, where others in the field believe they have done great work.

My two days with my new colleagues and friends were the best two days of my professional life, without question!! This is an incredible group with which to be associated, and part of our time together was just getting to know each other and the similarities and differences between our education systems, cultures and environments. In the end it became clear that kids are kids, and we all have the same needs and wishes for our students. It is fascinating to learn of the teachers in the Middle East who are working with refugee children who are on the run from war and terror groups. It is heartbreaking to hear from a teacher in India how families living in the slums have their daughters get married in arranged marriages at the age of 12 or 13, only to see them be forced to go into the sex trade for income - these are the girls she works with. Or an amazing man from Ghana who has needed to develop methods for deradicalizing kids who come out of certain madrasses or are being recruited by radical groups. Or the teacher from Haiti, who still is coping with widespread destruction left over from the earthquake six years ago.

Our mission is big and long-term: to use any influence we might have or gain in the future to help improve the status of our profession, and to help as many kids globally as we can. For example, we have already been proactive by writing to Ban Ke-moon, the Secretary General of the U.N., to see if there are any ways to help the millions of refugee children fleeing Syria, many of whom have not been in a school for several years since the civil war began (and many of whom are now running from ISIS). We have working groups thinking about what resources we can provide the world's teachers to help them in training and in their classrooms. We are thinking of how to influence policy makers and improve education at the systemic level, with less demand for standardized testing and more emphasis on skills students need in modern times. Note there were dozens of ministers of education at the conference, including Arne Duncan, and several former heads of state (such as Tony Blair), so these are people in our network with whom we now have contact. We are discussing and forming collaborations between our schools so students can learn from each other about culture, issues, commonalities, and the creation of joint projects, using technologies for the common good. We are thinking about what a science classroom should be doing if we are serious about "21st century skills." We are thinking about how to get students active in all subject areas, and how we can transform schools to some level of multidisciplinary work in order to allow students to develop creative and innovation skills, which are a must in the modern workplace.

To a person, all of us involved with this group are committed to working on these issues for the rest of our lives. It is exciting, but also daunting given the political environments in many countries. But our kids are worth the effort!! Each year we will have 50 more ambassadors, as we continuously branch out our network across the globe, gaining influence and making impacts, both small and large, as we try to change the world over time!!

A special THANK YOU goes to the ETHS Alumni Association!! Without their very generous grant, I likely would not have been able to go to the conference in Dubai!! To my ETHS colleagues, this is a wonderful group that offers mini-grants to faculty with ideas they want to try in their classrooms, so please inquire if you have cool ideas that will help your students!!

## Sunday, April 3, 2016

### It is OK to fail - that is what it takes to be creative and to learn!!

In our way of doing school, a theme has arisen from many people who think about education and what the modern school and education system should look like (and it is NOT what reality is!). In study after study, and anecdote after anecdote, the theme is we all need to be ready, willing and able to FAIL at things we try!!

However, as Sir Ken Robinson and many others have said (myself included), our present test-crazed way of doing school makes failure the worst thing a student can do. In order to be creative or to make a great discovery, one needs to try things over and over! Picasso did not whip out masterpiece after masterpiece - he had countless mediocre paintings and pieces of art in between - that is, countless 'failures.' The same for Mozart. The same for any notable and famous author, who was rejected dozens of times by publishers before finally getting a break, and then having to do numerous edits. And for the scientist or engineer, who have endless failed experiments or prototypes that need to be reworked and troubleshot. It is a rule of thumb that to become an expert at something, one needs 10,000 hours or experience and practice.

Check out this TED talk by Adam Grant, who has noted three key traits of creative people: i) their willingness to procrastinate, at least a bit, in order to refine an idea or to give themselves time to think about other ways of doing something; ii) fear and doubt...the most creative people are still humans, and we all have self-doubt and a fear of failure...however, the creative, successful person is more afraid of NOT TRYING, rather than just being afraid of being wrong; and iii) every creative person has countless failures before getting it right (you must accept the fact that everyone's first draft or attempt at something will almost certainly not be the best way of doing it!).

## Monday, March 28, 2016

### 'Smarter Every Day' video on some different magnetic tidbits!

This comes to us thanks to Marc B., a former student who loved magnetism and still spends (too much, in his words) time watching anything he finds on the topic. It is perfect for us since we are wrapping things up with magnetism! Check it out! By the way, the website for the polymagnets company, which custom designs magnets with any configuration, is here.

## Monday, March 21, 2016

### Sir Ken Robinson on Creativity (or the lack thereof) in Schools

This is one of my favorite TED talks. Keep in mind creativity and innovation are two of the most important 'skills' or qualities students need to develop in this globalized, technological economy. Let me know what you think!

### A few interesting EM induction examples

As we study electromagnetic induction, a developing technology application is wireless charging, which can go by the name of wireless power or inductive charging. This process uses electromagnetic fields to induce charge in devices, so there is no need for physical contact (hence the use of 'induction'). Presumably this would need to make use of AC currents, in order to cause changes in flux (and apply Faraday's law of em induction).

How do inductive stoves work, where the stove would not necessarily be warm/hot to the touch, but put a copper pot on it and the pot heats up rapidly?!

Another famous example is an electromagnetic pulse, or EMP. These are bursts of electromagnetic energy, and many phenomena can produce such bursts, from lightning to solar flares to nuclear blasts. These can cause damage to electronics systems, for instance, since currents will be induced in circuitry.

Think about where else there could be induction phenomena in your life!

## Friday, March 18, 2016

### For Classes on March 18

Happy Friday everyone!

Periods 1-2, 8-9:
Yesterday you saw something on Faraday's law for a moving hoop/changing area example. This is the case where induced voltage = B dA/dt. Today extend on this by looking at cases where a second force is trying to push a circuit through magnetism, such as dropping a metal hoop into a B-field. What you will see is that, because this process depends on speed, it ends up looking a lot like air friction and terminal velocity from last year! Weird, but true. Remember the case of you trying to swing the metal hoop through the big magnet, and you felt the forces on it trying to slow it down (this is a magnetic brake). Take good notes so you can try to make sense together of the home work problems - see if you can complete things before leaving.

Homework set:
The glider problem on page 6 is based on yesterday - use the notes on page 2 and 3, could be helpful
The 1990 problem on page 7 - notes on page 4 could be helpful
The challenge problem is on page 9! Have fun!

Periods 3-4:

Take a look at the problems for yesterday, and see if there is any consensus. Ampere's law depends on the current inside the region you are looking at, analogous to Gauss's law depending on teh charge inside the region.

One application of Ampere's law for straight wires, where B = (mu)I/(2*pi*r), is to get the force between two currents. Check out a video on the forces between two long wires with currents - they are both producing magnetism, so the wires should either attract or repel each other! Take good notes, this will be needed for some of the homework. Note that the force on currents is F = IL x B, where L is the length of a segment of the wire.

Then, take a look at a video on the initial exposure to Biot-Savart law. This is the rule that allows us to determine the magnetic field for things more exactly (Ampere is only for long wires, solenoids, and toroids, so it is limited). We will look at what a single moving particle does in terms of producing a magnetic field. Take good notes, because we will build on this.

Try the following from the packet:
Ch. 28 #8 (B-S law), 31 on page 7
AP Prob from 1983, page 11

## Thursday, March 17, 2016

### Classes for March 17

Periods 1-2 and 8-9:

We will dive into the electromagnetic induction material! Check out two videos, for the case where we have a constant magnetic field and a moving chunk of metal or circuit. This is the case of
emf = induced voltage = -B dA/dt. The first is about just moving a piece of metal through a magnetic field. The second is about moving a circuit into or out of a B-field, where the area is changing. Take good notes, and you can try AP problems from 1981 and 1984 (pages 5 and 8 in the packet).

Also, start doing an error analysis on the last magnetism quizzam (solutions have been on the web site).

Periods 3-4:
3rd period you will need to do the school survey. After this, check with each other about answers to last night's set. Once done, then watch a video and take notes on Ampere's law - this is similar to Gauss's law for electric fields, only for magnetism!

Try the AP problems on pages 8 and 9 in the packet from yesterday.

## Monday, March 7, 2016

### Some links for classes the week of March 8-11

While Doc V is out of town, here are some links:

Periods 1-2, 6-7, 8-9:

On Tuesday, after reaching consensus on the homework problems, check out a video on rolling without slipping. This is the type of motion we would expect to have for things that roll. When there is NO SLIPPING, this means we have no heat being generated, and we can use the relationships s = R*(theta), v = Rw, a = R*(alpha). Take good notes, and feel free to replay any parts that are confusing. Also, on the blog is a video on the equilibrium stuff we did last week (balancing torques), in case anyone wants to see another example of left = right, up = down, and cw = ccw.

After watching the video, see if you can make it through the 1997 problem on page 18 of our packet; work in small groups to see if the video made any sense. Then you can try some of the homework problems before leaving: Page 13 of packet, Ch. 9 #83 or 84 (choose one); and page 14 of packet, the AP Problem from 2002. These all make use of energy! Remember, the only new thing is adding in (1/2)Iw^2 for rotational motion.

On Wednesday and Thursday, Adam is in!! For links to the lesson, go to Adam's web page. Have phun!

On Friday, someone can pull up the solutions to the 2002 problem from Tuesday and see how it went together. Then check out a video on something tipping over, with NON-constant angular acceleration. Take notes on this. You will then have time to try a problem from 1999, on page 15, which builds off the video. Also, you can take a look at the problem on page 19, from 1994, making use of a few ideas from energy.

Periods 3-4:

On Tuesday, before going back to the lab, check out a video on charged particles moving through magnetic fields (B-field). Take good notes, we will be using those later. Then get back into the lab and try to complete it before leaving. You will need the data from the graph portion for when Adam is here Wednesday and Thursday.

For homework, try to make sense of the Band Theory Review on page 3 of our packet. This gets into the difference between conductors, insulators, and semiconductors from a quantum point of view. Check out the video on this band gap theory as a guide, and try to summarize it on page 3.

On Wednesday and Thursday, Adam is in!! For links to the lesson, go to Adam's web page. Have phun!

On Friday, watch the Nova video called "Magnetic Storm," and answer the questions on page 10 of the packet. These will be collected next week. If there is time, there is also a video on mass spectrometers which you should watch in class (or at home if not enough time), in order to do the homework problem on page 13 (from 1984).

Thank you all for your cooperation this week, and for all the support! I am really proud of and thankful for each of you! I cannot wait to come back and have some discussions about all we are working on out in Dubai.