center of mass

"Some prophecies are self-fulfilling But I've had to work for all of mine Better times will come to me, God willing Cause I can't leave this world behind" -Josh Ritter You sure can't leave this world behind. At least, not very easily. The reason for it, of course, is gravity. Image Credit: Physclips, via the University of New South Wales' School of Physics. Here on the surface of the Earth, the gravitational potential well is pretty large; large enough that there's no easy way off. Sure, you can pour a huge amount of energy into a rocket to try and overcome this gravitational potential…

Of course I am talking about Arnold Schwarzenegger. After looking at how many bullets he carries in Commando, I remembered this scene (also from Commando) (warning: maybe some not great language and some killing. You have been warned) If you don't want to watch that clip, here is a shot (sorry for the quality). Clearly Arnold is strong, but there is more than strength involved here. Oh, don't bring your "he did it with wire stuff". I am not buying that. Also, I am talking about THE Arnold - he is real. I am not talking about the character in the movie (not real). Now for some physics…

Was the moonwalk fake? No, not the Apollo landings. I am talking about Michael Jackson's moonwalk. You got to admit, he had a big impact on a lot of stuff and this is my way to give him respect - physics. I am sure you know about the moonwalk. Maybe you can even do the dance move yourself, but how does it work? First, here is a clip of MJ doing his stuff. As a side note, I can't remember where I saw it but there was a great discussion of the history of the moonwalk. If I recall correctly, some were saying Michael didn't create this move. One thing is for sure, he made it popular. Now…

This is one of my favorite demos. Easy to do and doesn't really require any equipment. The basic idea is that you support a meter stick horizontally with two fingers. Slide your fingers in and they will both meet at the center of mass. Here is a video. Meterstick friction demo from Rhett Allain on Vimeo So, how does it work? To explain this, you need to understand friction and equilibrium. Well, nobody really understands friction - but anyway.. First, what is equilibrium? Equilibrium means that an object's motion does not change. For this case that means that both it's velocity and it…

This is something I have thought about for some time. It is also something I (as a father of 4) have a lot of experience with. The problem is these infant car carriers. In the car they are not a problem. The problem is out of the car. Not sure what I am talking about? Here is a picture: I don't mean to attack the infant carrier industry. I am sure some people really like these things. For me, there is only two situations that are good for taking the seat out of the car. In a restaurant. The infant seat works well with those toddler high chairs. Most of the current infant seat…