Physics

A 10 kg object is lifted vertically upward by 5 m, in this case, gravity does negative work.

When an object is lifted upward, gravity acts downward, opposite to the direction of motion. Therefore, gravity does negative work.

Option A: A ball weighing 20 N falls freely for 3 m.

Positive work by gravity: Gravity is acting in the same direction as the ball's motion (downward), so gravity does positive work in this case.

Option C: A box is pushe...