A line of best fit passes between a set of data points on a graph to show the pattern.

Variables are directly proportional when one is a constant multiple of the other.

A spring is elastic when it returns to its original length after forces are removed from it.

Hooke's law describes the behaviour of a spring when it is stretched.

Hooke's law

Science

In the Particle explanations of density and pressure unit, pupils will build on this knowledge to learn how the arrangement and movement of particles in solids, liquids and gases explain density, pressure, floating and convection.

In the Forces unit, pupils learnt how to accurately describe and explain the actions of forces in a range of situations.

This unit explores forces, deformation, Hooke’s Law, moments, and work done. It covers pressure in liquids, atmospheric pressure, upthrust, and equilibrium, as well as simple machines and force-extension relationships, highlighting how forces affect motion, friction, and object deformation.

Hidden forces

Physical activity and equipment requiring safe use

Passes between data points on a graph to show the pattern.

When one variable doubles, the other is doubled.

Returns to its original length when the forces are removed.

A description of the behaviour of springs.

Match the key word or phrase to the definition.

The length doubles for each newton of force.

The extension is independent of the force acting.

The extension increases the same amount for each newton of force.

All springs stretch the same amount per newton.

Which statement about springs is correct when they are stretched?

What happens to the extension of a spring if the force acting on it is increased from 6 N to 18 N?

It is a series of lines that connect all the data points exactly.

Which of the following describes the line of best fit for a graph where the two variables are directly proportional?

It will spring back to shorter than its original length.

It will spring back to its original length.

It will spring back to longer than its original length.

It will not spring back and stay at the length it has reached.

Some pupils add too much force to a spring. For each extra 1 N they then add, the extension increases much more than expected. What will happen to the spring when the force is removed.

The graph shows the extension of a spring for different forces acting on it.  What is the extension per newton for this spring? Give your answer to two significant figures.

Complete the statement. The word used to describe the force on an object due to a gravitational field is ...

A pupil puts different forces on a spring. Starting with the smallest extension, sort the forces into order of the extension they cause.

The figure shows a spring before and after a weight has been added. What is the extension of the spring when the mass is placed on it?

Use a shorter spring to make the extension shorter.

Use a set square to make sure the measurement is horizontal.

Move the ruler further from the spring to keep it balanced.

Use a longer spring to make the extension shorter.

The photograph shows a pupil measuring the extension of a spring. How could the pupil improve the accuracy of the measurement?

The gravitational field strength on Earth is 10 N/kg. What size mass will have a weight of 1 N?

This will help loosen the spring and make it stretch better.

The masses may have changed after they were added.

To help check the accuracy of the measurements.

So that a wider range of masses can be used.

Why is it important to measure the extension of a spring when masses are taken off as well as being added?

Content guidance

Risk assessment required - equipment

Adult supervision required

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

Hooke's law

Lesson outcome

Content guidance

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