Front

Which of the following is NOT a store of energy? Kinetic, Gravitational Potential, Elastic potential, Thermal, Sound

Back

Sound

Front

Which of the following is NOT a transfer of energy? Heating, Kinetically, Mechanically, Electrically, Waves

Back

Kinetically

Front

What energy transfers occur when a ball is thrown vertically upwards?

Back

Energy is transferred from the kinetic energy store of the ball to its gravitational potential energy store. Energy is also transferred from the kinetic energy store to the thermal energy store of the ball and the air as work is done by air resistance to slow it down.

Front

Which object has the most kinetic energy? E_k = 0.5 x mass x speed^2. Options: A 10 kg mass with a speed of 5 m/s, A 5 kg mass with a speed of 10 m/s, A 2 kg mass with a speed of 20 m/s, A 0.1 kg mass with a speed of 100 m/s.

Back

A 0.1 kg mass with a speed of 100 m/s.

Front

Which object has the most gravitational potential energy? Options: A 3 kg mass, 5 m above the ground on Earth (g = 9.8 N/kg), A 4 kg mass, 4 m above the ground on Venus (g = 8.9 N/kg), A 10 kg mass, 5 m above the ground on Mars (g = 3.4 N/kg), A 9 kg mass, 11 m above the ground on the Moon (g = 1.6 N/kg)

Back

A 10 kg mass, 5 m above the ground on Mars (g = 3.4 N/kg)

Front

Calculate the elastic potential energy stored in a spring with a spring constant of 200 N/m that has been stretched from a length of 117 cm to a length of 127 cm. Use the equation: E_e = 0.5 x spring constant x extension². (Extension must be in metres, m)

Back

1.0 J

Front

Correct equation linking work done, power, and time?

Back

work done = power x time

Front

A toaster takes 200 s to transfer 180,000 J of energy. What is the power of the toaster?

Back

900 W

Front

An electric motor transfers 24 J of energy usefully, but wastes 16 J of energy in doing so. What is the efficiency of the motor?

Back

24 J ÷ 40 J = 0.6

Front

What would an efficiency of 0% tell you about the energy transfers of a device?

Back

All the energy that is transferred is to an unwanted energy store.