If the maximum load carried by an elevator is \( 1400 \, \text{kg} \) (\( 600 \, \text{kg} \) – passengers + \( 800 \, \text{kg} \) – elevator), which is moving up with a uniform speed of \( 3 \, \text{m s}^{-1} \) and the frictional force acting on it is \( 2000 \, \text{N} \), then the maximum power used by the motor is ______ \( \text{kW} \) (\( g = 10 \, \text{m/s}^2 \)).
