Question

pablo prepares to lift a barbell. during which stage of the lift does pablo do work on the barbell? when he holds the barbell up above his head when he applies force to the barbell but has not moved it when he lifts the barbell from the floor to his chest when he lets go of the barbell and allows it fall to the ground

Explanation:

Work is done when a force is applied over a distance. In the first two options, there is no displacement while force is applied. In the last option, gravity does the work. Only when lifting the barbell from the floor to the chest is force applied over a distance.

Answer:

when he lifts the barbell from the floor to his chest