Question

The change in potential for a closed path in a conservative force field is nil. Does this imply that the force on an object going along the path is also zero? Explain with an example?

Answer 1

For a closed loop, the combined work done is zero for small segments of the loop. For individual segments, the work done is either negative or positive. So, the force does work on individual segments.

For example, the work done by gravity when a ball is thrown up is zero for the round trip. But, the work done by the gravity from the lowest point to the highest point is not zero, which means the force is not zero. When the ball comes down, the work done is equal and opposite to the work done when moving up. So, the combined work done is zero.