Under Pressure

Happy Thanksgiving. Anyways, the only thing I do on Thanksgiving is play video games, eat, and watch some football. The last of the three NFL games on Thanksgiving was the Broncos vs the Giatns in Denver, the mile high city. Being in that altitude makes some players have those oxygen masks since the air is so thin since their altitude is higher. That also has some stuff to do with atmospheric pressure. Everything in the Earth's atmosphere is under atmospheric pressure, but depending upon where a person is located, the pressure varies. Even though most people think air is nothing, air has mass, which is why atmospheric pressure occurs since all the air is pushing down on you. So most people can't even notice it, but when they change altitude, sometimes their ears pop, which is because of the varying pressure outside and inside their body. That can be why ears pop, headaches occur, sinus pressure happens, and most of all atmospheric pressure, all because of air.

Going back in Physics

Well, this chapter we were talking about planetary gravitation and all that stuff, and I was all like "how am I supposed to write a blog about that?" So I'm not going to write a blog about that, I'm going to write about torque again. And the subject is Figure skating, since I was watching football, and accidentally went up a channel to figure skating. And as I watched it, the dude did one of those things where they curl up and spins super fast. And then to slow down, he put his arms and leg out and slow his spinning. Torque is how it works. If he were to spin with a large radius , he would go slower since the force would be the same, but the torque would be greater. If he compacts his body, the radius gets smaller, and the torque gets smaller, so he is able to spin faster. Exactly why, I'm not sure, but it has something to do with center of mass and gravity...Which reminds me, I have to do my problem set. (I'm not going to say it this time, Tracy).

"Triple salchow BEE-YOTCH"

Torque Dummies

As we started learning about torque in rotation and such with equlibrium and what not, I had a hard time thinking up stuff to talk about in this blog. After watching the Steelers lose today (total bs), I thought of football practice this week. Many teams have those football dummies all lined up on a sled, which they practice blocking. The thing about the blocking dummy is that it is all about torque.

See, if the lineman push the sled on one side, the sled will rotate since the torque makes it go one way. If the players all lineup on each dummy and push with equal force, the sled will not rotate and will just move forward. The reason is because of all the forces acting on the sled cancel out, since they are oposite of the center of rotation, so the sled has no net torque. Also, if a player pushes the middle dummy, there will be no rotation, since the radius from the center of rotation will be zero, so there won't be any torque. If, of course, the center of rotation is in the middle of the sled. So if the player lines up on the outermost dummy and pushes, the radius will be greater and there will be rotation. Of course, football sleds are only for practice, since in the game the opposing line won't have a center of rotation or be dummies. Hopefully the Steelers practice hard the rest of the season...Go Steelers!

rotating radi

Well, last week I talked about some examples of centripetal force. This week I got some more, but they show some stuff that has to do with radi. The first was that rotating plate in the microwave, since I made popcorn today (Doc's favorite food?). If I put the popcorn in the middle of the plate, it doesn't move that much. But if I put it on the edge, it spins 'round and 'round. Another thing like that is the "lazy susan" in my house, which is like a circular, rotating, cuboard. If I put something in the middle of the susan, I'll always have to reach into the middle to grab it, as opposed to putting it on the outside and rotating it in front of me. What does this have to do with Physics? Good question, and the answer is everything. But I was just thinking aobut how the radi affects everything in rotational motion. If the radi is huge, compared to small, the item will have to move much faster to make the same angular displacement. This alos reminds me of my second physics post about marching in the parade. The week before the parade we marched outside and practiced going around turns. The thing was that if we wanted to keep a straight line, the people on the outside had to quicken step, and the people inside had to slow down. It's all about the radi to the center of rotation. Go Steelers! Also, that picture of the lazy susan needs to be rotated...it's sideways

Examples of Centrifugal force

Last Friday, Doc told our class to look for examples of centrifugal force, so I did that. I just walked around my house and took pictures of stuff I thought displayed centrifugal force. Lets see.. Got a drying machine, since it spins around. A fan, since that also spins around. A toilet paper roll (it spins around too). My spinning chair, a planetary mobile, and one of those spinning ball thingys...just look at the pictures. Anyways, Doc also said to look for the inward force in such cases. It is hard for me to see these things. In the dryer, the inward force is the walls? The fan has the individual blades connected to the rotating center. I could go on and on, but the point is that all these things have some sort of inward force. Even if I still don't know what it is...go steelers!