Physics 1: Friction and Football

I figured the best way to augment my growing Physics education was to do a journal that shows real life applications (as in the hows and whys) of Physics. Today's is okay, but Physics can be a messy study and so it should be said that you're reading this at your own risk. Remember to duck if told to and beware of science content. :P

There are probably innumerable applications of Physics to any sport, but the one that I've gotten is an example that concerns friction and football (and to some extent, basketball). Let's say you've got two football players--> one has the ball and is running for a touchdown, but he's bigger than the guy who's trying to tackle him. How can the defender stop him?

First of all, though, do you know why it's so difficult to stop him? It's not just weight, it also has to do with the friction between the player and the ground. In fact, if there was some way to negate that friction, the defender would be able to stop him, almost no matter the difference in size and strength.

What football coaches instruct their defenders is to push up from under the shoulder pads of the other player. Technically, it doesn't really lift him off the ground (normally), but it reduces that friction enough to be able to keep him from getting past the defender.

For those of you who aren't so sports-oriented, consider the example we were actually shown in class: let's say that two people who are very different in strength play tug-of-war in the classroom (i.e. tile floors). Tug-of-war doesn't allow a person to put their hands on the other player so how can they negate friction? Ever slipped on a piece of paper in a messy room? Exactly. There is enough friction to keep the person on the paper, but there is very little friction (or less, anyways) between the paper and the floor. The person who is not standing on the paper (even if they are the one with much less strength) has a very immediate advantage and could probably drag the other along the floor for some distance.

Any questions, comments, or additions, feel free to communicate with me (comments, email, dA, etc).

Next Physics Post: Mass, Acceleration, and Karate Boards (and Certain Body Parts)