Energy input of a pulley system

Question

A pulley system is used to raise a 30 kg load upwards at a steady rate. The energy input to the system is 1000 J every second and the efficiency of the system us 50% (that is, half the energy input is used to do work on the load). How fast is the load being raised?

Answer 1

Power = Force x Velocity or Velocity =Power/Force

Velocity = (1/2)(1000) Kg-m²/sec³/(30 Kg x 9.8 m/sec²) = 1.7 m/sec