A motorized winch with an efficiency of 75% is used to raise a load of mass 120 kg vertically at a constant speed of 2.5 m s-1.
Taking the acceleration due to gravity to be g=9.8 m s−2g = 9.8\text{ m s}^{-2}g=9.8 m s−2, calculate the electrical power input to the winch motor.
2.21 kW2.21\text{ kW}2.21 kW
2.94 kW2.94\text{ kW}2.94 kW
3.92 kW3.92\text{ kW}3.92 kW
0.40 kW0.40\text{ kW}0.40 kW