Question

Olympic weightlifter Zoe Smith lifts a 58 kg barbell over her head, 2.1 meters above the ground in 0.6 sec. How much power must she generate to lift the barbell from the ground?

a) 0 W

b) 58 W

c) 120 W

d) 720 W

e) 1990 W

Answer 1

Mass = 58 kg Height = 2.1'm Let g = 9.8 m/s2 So work done = mah = force x displacement (mg) (h) = 58 x 9.8 * 2:19 = 1193.64 Joules Now power required = Work Time = 1193.63 0.6 1989.4 ~ 1990W = power = 1990W