The extension of a rubber band is its change in length.

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

A rubber band is elastic; it returns to its original length after forces are removed from it.

Rubber contains long molecular chains, that uncoil when it stretches.

Stretching rubber

Science

Gravitational force and weight

Stretching springs

Hooke's law

The force of a floor

Levers

Turning forces

Floating, mass and shape

Pressure

Pressure at different depths and heights

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

material returns to its original length after forces are removed

the increase in length when a material is stretched

when one variable increases, the other increases at the same rate

Match the keyword or phrase with the explanation.

An equal force is applied to both ends of a rubber band. What happens to the rubber band?

The figure shows a rubber band before and after it has been stretched. What is the extension of the band?

Which of the lines on the graph shows the extension of a rubber band when a force is applied?

The extension is directly proportional to the force applied.

The rubber band behaves elastically when the force applied is removed.

The extension increases with the force applied.

The rubber band becomes permanently stretched when a force is applied.

Which of the following statements describe the extension of a rubber band when it is stretched?

The long chain molecules are closely coiled together.

The long chain molecules begin to uncoil but this is difficult at first.

As more force is added, the molecules unwind and become easier to stretch.

The molecules approach their maximum length, becoming more difficult to stretch.

Eventually, the long chain molecules are fully unwound and stretch no further.

Order the following statements to describe the stretching of a rubber band as an increasing force is applied.

Complete the sentence: The increase in length of a spring with a force acting on it is the {{}}.

Which word is used to describe something that returns to its original shape when the forces acting on it are removed?

What is the extension of this spring when a force of 30 N acts on it?

The total length of a spring is directly proportional to the force acting on it.

The extension of a spring is directly proportional to the force acting on it.

The extension of a spring is directly proportional to its mass.

The extension of a spring is inversely proportional to the force acting on it.

The total length of a spring is inversely proportional to the force on it.

Which of these is a statement of Hooke's law?

The spring obeys Hooke's law for forces below 40 N.

The spring does not obey Hooke's law for forces over 45 N.

The spring does not obey Hooke's law for forces less than 45 N.

The spring obeys Hooke's law for forces above 45 N.

According to the graph, which of these statements are true?

A pupil collects the data shown during a spring experiment. Use the data to predict the extension if the force used was 8 N. Give your answer in cm to the nearest whole number.

Stretching rubber

Lesson outcome

Content guidance