Forces used to bring moving objects to a stop.

The time taken for a moving object to stop.

The product of the mass and velocity of a moving object, p = m × v.

Parts of a car designed to crumple during impacts, increasing the stopping time and reducing the stopping forces.

These inflate rapidly in collisions and protect passengers from impacts with hard surfaces.

Stopping safely

Combined science

In the Gravity in space unit, they will build on this knowledge to learn about centripetal forces, orbital motion, stellar evolution, red shift and the big bang.

In the Energy of moving objects unit, pupils learnt how to calculate the amount of energy of objects have because they are moving, stretched or in a gravitational field; and to calculate energy transfers using knowledge of energy conservation and dissipation.

This unit explores forces, interactions, and Newton’s laws, including motion, rotation, and momentum. It covers reaction times, stopping distances, and deceleration dangers. Emphasis is on force diagrams, calculations, experiments, and evaluating methods for accuracy and safety.

Forces make things change

Subjects which particular individuals may be sensitive to, eg, adoption, migration, bereavement or death, divorce, poverty, deprivation.

Depiction or discussion of sensitive content

The product of mass and velocity of a moving object, $$p = m × v$$.

Parts of a car designed to crumple and increase stopping time.

Inflate in a collision and protect passengers from impacts.

Match the following key terms to their definitions.

A lorry is attempting to slow down to a stop. What will happen to the stopping time and stopping distance if the braking force increases?

These stretch to increase stopping times and reduce impact forces.

These collapse to increase stopping times and reduce impact forces.

These inflate to form a protective cushion, increasing stopping times.

Match each of the following safety features to its function.

It lowers the initial momentum of objects.

It produces larger forces to stop things more quickly.

It produces smaller forces to stop things more quickly.

Why does padding decrease the size of impact forces?

A lorry of mass 5000 kg travels at a velocity of 18 m/s. The brakes produce a braking force of 15 000 N on the wheels.
Calculate the stopping time for the lorry. Give the unit.

Two cars have the same momentum of 12 000 kg m/s. It takes one car 0.20 s to stop, and the other one stops in 0.05 s.
Calculate the difference in the stopping forces acting on the cars.

Match the following quantities to their unit.

stopping distance = thinking time + braking distance

stopping distance = thinking time + braking time

stopping distance = thinking distance – braking distance

stopping distance = thinking distance + braking distance

stopping distance = thinking distance × braking distance

Which of the following is the correct equation for stopping distance?

Which of the following is the correct equation for momentum?

The momentum of the ball increases as the ball falls.

The mass of the ball increases as it falls.

A ball is dropped vertically from 10 m. As the ball falls, which of the following statements are correct?

A car has a mass of 800 kg and velocity of 4.0 m/s.
Calculate the momentum of the car.

A motorcycle of mass 200 kg, slows from 14 m/s to 12 m/s. What is the change of momentum for the motorcycle?

Content guidance

Depiction or discussion of sensitive content

Adult supervision recommended

This lesson will be removed by end of Summer Term 2025.

Stopping safely

Lesson outcome

Content guidance

This lesson will be removed by end of Summer Term 2025.