when a -3.72×10^-4 C charge moves from point a to point A to point B it's electric potential energy increases by 0.218 J what is the potential difference between A and B

How is the gravitational force related to the distance between two objects?

Aperson stands on a platform, initially at rest, that can rotate freely without friction. the moment of inertia of the person plus the platform is ip. the person holds a spinning bicycle wheel with its axis horizontal. the wheel has moment of inertia iw and angular velocity ωw. take the ωw direction counterclockwise when viewed from above. part a what will be the angular velocity ωp of the platform if the person moves the axis of the wheel so that it points vertically upward?

In addition to gravity, what is the other predominant force that affects the motion of a pendulum?