Question

A weight lifter lifts a barbell from the ground, raises it at a constat velocity and holds it motionless over his head. How does the force of the lifter compare with the wieght of the barbell at different stages of the lift?

Answer 1

w=F*d
d= 0m
0J....no work

Answer 2

when the barbell is being lifted its weight is different than when it is stationary

Answer 3

why don't you answer it yourself?

Answer 4

A weight lifter lifts a 550 N weight 1.25 m over his head in 2.5 seconds. What is the power of the weight lifter?