Question

A 240-V electric motor is 90% efficient, meaning that 90% of the energy supplied to it ends up as mechanical work. (a) If the motor lifts a 200-N weight at 3.1 m/s, how much current does it draw? (b) Let's check your answer in part (a). We expect that the less efficient the motor operates, the larger the current that must be drawn to supply the required power. Does the expression for the current drawn you have derived in part (a) match this prediction?

Answer 1