Question

work done by gravitational force negative and positive
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Answer 1

Answer:

Well, gravity always acts downwards, right? So the force of gravity is downward, but the ball is moving up. So notice that the force and the displacement are in the opposite direction. That means during this motion, gravity is doing negative work on that ball.

Answer 2

Well you see my friend gravity is always negative but if you change its frame work and see it from acceleration point of view it is positive. So it is a force which acts on mass to accelerate it. From the view of the accelerating object it is positive.

Hope it helps.