Question

When is the work on a spring negative and when is it positive

Answer 1

You pull a spring to extend it. The force you exert on the spring is in the same direction as your displacement. You have done positive work on the spring. The force that the spring exerts on you is in the opposite direction to its displacement so the spring has donenegative work and the POSITIVE WORK IS MOVING A BOX IN A APPLIED FORCE DIRECTION

Answer 2

Answer:

When the spring is being stretched or shortened, the spring force acting on the mass is in a direction that is opposite to the direction of the displacement of the mass and so thework done by it is negative.