Question

give an example in each where work done by a force is zero and positive and negative

Answer 1

Example for when work is zero.

When the displacement of a body is zero. The work done is said to be zero. When you throw a ball up it comes back to the earth. There the work done is zero.

Example for when the work done is positive.

When a culie with a load on his head climbs up the stairs. The work done is said to be positive.

Example for when the work done is negative

When the culie comes down the stairs with a heavy load on his head. The work done is said to be in negative

Answer 2

Zero: when a coolie walks on a horizontal ground with a load on his head.

Positive: when a free falling body is thrown down from up(downwards).

Negative: when a free falling body is thrown up from down(upwards).

Hope it helps....mark brainliest