How to do Inelastic Collisions where bullets stick in blocks

Here is a case where bullets are fired into blocks, and by measuring what happens afterwards allows us to figure out the speed of the bullet before the collision. A classic example is a ballistic pendulum, and this is compared to a similar spring problem. Because the collisions are INelastic, kinetic energy before and after is not the same (KEo > KEf). But, conservation of momentum is what connects the before and after pictures of such collisions. Check it out.

Dark Matter - Interactive Forum from Scientific American

Check out the interactive discussion about dark matter, a favorite topic in modern physics, particularly in the astrophysics and particle physics fields. Dark matter is a generic term for anything that cannot be seen in the electromagnetic spectrum, but affects other objects gravitationally. This could be known matter such as neutrinos, neutron stars, brown dwarfs, or just unseen stars and galaxies. Or, it could be new forms of matter outside of the standard model in particle physics. There are names like WIMPS, MACHOS, axions, and others. Always a good time checking into cutting-edge ideas!

Spring Problems and the use of Energy

Springs provide a nice example of NON-constant force. We know Hooke's law, F = -kx, where x is the displacement of the spring from its equilibrium position. Keep in mind the - sign is for direction: the force always tries to bring a spring back to equilibrium, which is in the opposite direction relative to the direction of the displacement (a point of stable equilibrium). Here are examples of using energy conservation to solve spring problems.

A Need for a Paradigm Shift in Education - Sir Ken Robinson

What do you think about the current education system? It is a factory-style process built for the Industrial Age. How should education systems look like for an age of globalization, though???? Check out the following video, which is an animated summary of a lecture given by Sir Ken Robinson, who has been a leader in real education reform, a need for creativity, and so on. In my humble opinion, this is a wonderful video presentation that should get you thinking!

Keep in mind that no solutions are offered as to how to change classroom teaching and learning to fit the new paradigm, but such presentations are most useful to get the general population thinking, and also to get policymakers (i.e. politicians who are in charge of education, and who almost exclusively have not taught before) thinking before they continue down the same status quo reform movements like No Child Left Behind (Pres. Bush) and even Race to the Top (Pres. Obama).

Please comment, as I really am interested in your thoughts.

Hubble Deep Field, 3-D!

A tip of the cap to former Chem-Phys student Lina, for passing along this link to me. It is really neat!

http://www.flixxy.com/hubble-ultra-deep-field-3d.htm

Words of Wisdom from Bill Gates

This is supposed to have come from a speech Bill Gates, who at any given time is either the first or second richest person on the planet. His point was to tell students the major differences between being in school and the actual world. I suspect most adults would concur on most, if not all, of Gates's observations. I'll let you enjoy his comments!

Bill Gates speech: 11 rules your kids did not and will not learn in school

Rule 1: Life is not fair - get used to it!

Rule 2: The world doesn't care about your self-esteem. The world will expect you to accomplish something BEFORE you feel good about yourself.

Rule 3: You will NOT make $60,000 a year right out of high school. You won't be a vice-president with a car phone until you earn both.

Rule 4: If you think your teacher is tough, wait till you get a boss.

Rule 5: Flipping burgers is not beneath your dignity. Your Grandparents had a different word for burger flipping: they called it opportunity.

Rule 6: If you mess up, it's not your parents' fault, so don't whine about your mistakes, learn from them.

Rule 7: Before you were born, your parents weren't as boring as they are now. They got that way from paying your bills, cleaning your clothes and listening to you talk about how cool you thought you were. So before you save the rain forest from the parasites of your parent's generation, try delousing the closet in your own room.

Rule 8: Your school may have done away with winners and losers, but life HAS NOT. In some schools, they have abolished failing grades and they'll give you as MANY TIMES as you want to get the right answer. This doesn't bear the slightest resemblance to ANYTHING in real life.

Rule 9: Life is not divided into semesters. You don't get summers off and very few employers are interested in helping you FIND YOURSELF. Do that on your own time.

Rule 10: Television is NOT real life. In real life people actually have to leave the coffee shop and go to jobs.

Rule 11: Be nice to nerds. Chances are you'll end up working for one.

Science and Democracy

I read a truly interesting book over the summer, called "The Science of Liberty" by Timothy Ferris, one of the best science writers we have today. The argument he poses is that the development of science is effectively responsible for the creation of American liberal democracy (not meaning the modern interpretation of liberal, which is associated with being a Democrat, but rather the creation of liberty as a basic human right). I wrote about this back in early July, but am pleased to see that others are taking interest in the book.

There is a new Skeptic article in Scientific American. In it, Michael Shermer gives his take on the premise of the book, and I encourage you to take a look at it and find out what you think. It is an interesting topic.

Let the Madness Begin!

Well, we are here, back in ETHS!! Welcome back. I anticipate a fantastic year as we pursue a journey to figure out some physics, and gain insight into how the universe works. This blog will have a variety of thoughts and questions throughout the year for us to ponder. It will have links to 'how to' videos for a large assortment of problems and concepts. From time to time I may request your feedback to certain posts, so we can get a class discussion going. It is important that you have some experience with using blogs since they are likely here to stay. We will do other forums in Moodle from time to time, as well, so we can make good use in sharing information and opinions with each other using a few different technologies. However, you are, of course, welcome and encouraged to leave comments any time you wish. You will need a Google account (by getting gmail, for example, at gmail.com).

Enjoy the first few days, and we'll get to work. I hope you had a wonderful summer, but it will be good to see all of you.

New School Year Almost Upon Us

In just a few weeks, we will be back at it at good ol' ETHS. I hope everyone has had a wonderful, relaxing summer, and is charged up to have some good times in Physics. I am looking forward to seeing everyone very soon.

Take it easy, and incoming seniors, do some work on those college essays now...you'll thank yourself when school is in session and those AP classes are loading you up with work. :-)

Evolution of Information

I will give the direct link to Zenpundit's post on this topic. It is a really interesting, non-technical, 8-minute history of the evolution of information since humans first began writing down information. Of particular interest is where information gathering and acessibility is headed in the next couple decades. I agree with the analysis presented in the video, and one can already see hints of things to come. We are in a 'pull' era, where individuals are expecting and demanding that they be able to gather information from all media resources, whenever and wherever they happen to be (this is a large part of the fate of traditional newspapers that cannot compete with online news sources, for instance; traditional newspapers are part of the 'push' era that we have been exiting over the last 5-10 years). This is also why 'smart phones' are becoming the tool of choice for millions, if not billions, of individuals worldwide, and they will take the lead in the 'pull' era.

An aside: It would be wise for educators to note this trend, accept it, and begin to allow students to use personal communications devices more frequently in the education process.