Help asap. which of the following use the most energy?

A500g object falls off a cliff and losers 100 j from its gravitational potential energy store. if the gravitational field strength g=9.8n/kg, how high is the cliff?

A-4.60 μc charge is moving at a constant speed of 6.80×105 m/s in the +x−direction relative to a reference frame. at the instant when the point charge is at the origin, what is the magnetic-field vector it produces at the following points.

An object resting on a table weighs 100 n. with what force is the object pushing on the table? with what force is the table pushing on the object? explain how you got your answer.