(a bodybuilder loads a bar with 550 newton's (-125 pounds)of weight and pushes the bar over her head 10 times. each time he lifts the weight 0.5 meters. how much work (j) does she do? ) if she pushes the bar 10 times in 20 seconds, how much power did she use?

Work = (force) x (distance)

Each time she lifts the weight, she does: (550 N) x (0.5 m) = 275 joules of work against gravity.

Each time she lets the bar down gently, gravity does: (550 N) x (0.5 m) = 275 joules of work against her muscles. 

The bodybuilder would do exactly zero work in the process of 1-up followed by 1-down.

Iam pretty sure its a sorry if im wrong