Torque is what turns things. When you want to twist off a bottle cap or push down on a lever, you are exerting a torque. Any force that works to turn an object around a central point or axis is a torque. By looking at the torques involved in a situation, you can determine if an object will rotate or not. The simplest way to look at torques (and the most useful for us) is to look at the balance.
How does torque affect a balance?
Let's say you set up the following on your Chaos set:
Take one long piece of track and balance it exactly in the center (use a ruler to find the exact center) on one of the mounts. Each of the above marked spots (A through G) are exactly the same distance from each other, with point D at the center. The distance each point is from the center is marked in parentheses. You should measure and mark with a piece of tape the points on your long piece of track just like this. You will notice that the piece of track balances with no weight on it if you've set it up correctly. When you put weight on either side the balance shifts (use pennies for weights - balls will roll away).
After experimenting for a little while you should realize that balancing does not only depend on how much weight is on each side, but on where it is placed on that side. In order to balance it, the weight times the position (the number in parentheses) must be equal on both sides. So, is it balanced if we place 3 pennies on C and one on G?
Yes.
3 pennies are on C. Its position number is 1. 3 x 1 =3.
1 penny is on G. Its position number is 3. 1 x 3 = 3.
3=3, so it is balanced.
Let's try a more complex example.
A: 1 penny (1 x 3 = 3)
B: 0 pennies (0 x 2 = 0)
C: 7 pennies (7 x 1 = 7)
D: 2 pennies (2 x 0 = 0)
E: 2 pennies (2 x 1 = 2)
F: 4 pennies (4 x 2 = 8)
G: 0 pennies (0 x 0 = 0)
3+7 = 2+ 8 = 10
They are balanced!
Will this work when objects are placed off of the measured spots?
Yes. Just as long as you measure the distance from the center for all balancing weights with the same units. For example, if you have one penny 2 inches from the center and 2 pennies one inch from the center, they will balance.