Kinetic Energy

Kinetic energy is the energy an object has due to its __________

• position

• mass

• gravitational force

• motion

Which of the following physical quantities can be used to calculate kinetic energy? (you may pick more than one)

• acceleration

• mass

• velocity

• time

• gavitational field strengths

What is the SI unit of kinetic energy?

• joule

• watt

• newton

• metre per second

A boy is running at the same speed as horse. Which of the following is true?

• The boy has zero kinetic energy.

• The boy has more kinetic energy than the horse.

• The horse has more kinetic energy than the boy.

• Both the boy and the horse have the same amount of kinetic energy.

A ball of 2 kg is being thrown at a speed of 5 m/s. What is its kinetic energy?

• 5 J

• 10 J

• 25 J

• 50 J

An apple of mass 100 g drops from a tree. It has a velocity of 10 m/s just before it hits the ground. What is the kinetic energy of the apple just before it hits the ground?

• 5 J

• 10 J

• 1000 J

• 5000 J

A car has a mass of 1000 kg. What is its kinetic energy when it is travelling at a speed of 90 km/h?

• 45 kJ

• 90 kJ

• 312.5 kJ

• 4050 kJ

A car of mass 1000 kg accelerates from rest with a uniform acceleration of 5  $ms^{-2}$ . Calculate its kinetic energy after 3 seconds.

• 12 500 J

• 15 000 J

• 112 500 J

• 225 000 J

What happens to the kinetic energy of a car when it brakes to a stop?

• The kinetic energy is converted to chemical potential energy.

• The kinetic energy is converted to gravitational potential energy.

• The kinetic energy is converted to thermal and sound energy.

• The kinetic energy remains unchanged.

A ball is thrown upward with an initial speed of 5 m/s. What happens to its kinetic energy as it moves towards its maximum height?

• The kinetic energy is converted to chemical potential energy.

• The kinetic energy is converted to gravitational potential energy.

• The kinetic energy is converted to thermal and sound energy.

• The is no change in its kinetic energy.