Posts Tagged ‘Force’
This is much harder to write than to show. The physics books usually have a problem about the tension in a horizontal cloths line with a single force hanging down in the middle. We can calculate these forces fairly easily, but hands on is better. The outdoor demonstration is to tie a strong rope between a tree and a car, then moving the car by applying a perpendicular force on the rope at the midpoint.
There is an even more effective demonstration of this that can be done in the classroom. It’s a martial arts escape from two attackers. I like to pick the two strongest and largest students as my victims. They each grab one of my wrists and pull away from each other. (They think they are so tough.) I then take a big step backwards and pull my hands towards each other. The two attackers move towards each other with a great deal of force and almost always bump into each other with surprising speed and force.