A force is applied perpendicularly to a wrench. How much torque is generated?

A child spins a top with a radius of with a force of . How much torque is generated at the edge of the top?

In ancient Greece, construction workers would use long levers to lift up boulders. Assume a boulder has a mass of and a certain construction worker has a mass of . The pivot point of the lever is placed from the boulder and the construction worker stands on the opposite end. How long does the lever need to be between the pivot point and the construction worker in order for the system to be in equilibrium?

Two children are trying to balance on a see-saw. One child has a mass of the other has a mass of . If the see-saw is balanced perfectly in the middle and the child is sitting at one end of the see-saw, how far from the center should the child sit so that the system is perfectly balanced?