Question

1. Does the center of gravity coincide with the fulcrum? Why?
2. why does a meter stick balance if the moments in one side equals the moment on the right side?
3. When do you solve for percent difference? Percent error?

Answer 1

1. Usually not, however, on uniform materials it can. For instance on a meter stick.
2. The sum of the moments about the fulcrum is zero. There is no net torque.
3. Question is just to vague. Answer depends on what one wants.