Question

What is meant by a positive work, negative work and zero work? Illustrate your answer with example?

CLASS - XI PHYSICS (Work, Energy and Power)

Answer 1

1. When the force acting on the body and its displacement are in same direction, positive work is done.
2. When the force acting on the body and its displacement are in opposite direction, negative work is done.
3. When the force is acting on the body but its displacement is 0, work done is 0.

Answer 2

Zero work is done when there is no displacement of the force is acting perpendicular to the body Eg - Work done by gravity when a body moves on a horizontal table

Negative work is done when the displacement is opposite to the direction of the applied Force Eg - Work done the gravity on a rocket going perpendicular upwards

Positive work is when the Displacement is in the direction of the applied force Eg - You are pushing a box

$W=F*s$