Answer

a) W = F x s (1) = 30,000 N x 18 m (1) = 540 kj (1)

b) 540 kj (1)

c) P = W / t = 540 kj / 24 s (1) = 22.5 kW (1)

d) P_in = P_out / efficiency (1) = 22.5 kW / 0.45 = 50 kW (1)