Question

A cat lifting a barbell of 2.5 kg a distance of 3 meters. How much work is done lifting the barbell? How much work is done if the cat holds the barbell over his head for 3 minutes?

Answer 1

Work = (force) x (distance)

Force = weight of the barbell = (mass) x (gravity) = (2.5 kg) x (9.8 m/s²)

Work = (2.5 x 9.8 newtons) x (3 meters) = 74 newton-meters = 74 joules.

It takes 74 joules to lift the 2.5-kg load 3 meters up off the floor.

After that, as long as the load is held motionless, no more work is done.