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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 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 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.