Chemical energy
Kinetic energy
Gravitational potential energy
Elastic potential energy
Electrical energy
Q. When a ball falls in air it loses ______ energy and gains _______ energy.
(Fill in the blank)
Q. When an electric heater is switched on, it transfers ______ energy by heating.
(Fill in the blank)
Useful energy and wasted energy
Efficiency equation
An electric motor is used to raise an object. The object gains 60J of gravitational potential energy when the motor is supplied with 200J of electrical energy.
Calculate the percentage efficiency of the motor.