Contact forces only act when objects are touching.

Friction is the force of one surface gripping or rubbing on another.

Objects moving through liquids and gases experience drag,  a force that acts against the object’s motion.

Non-contact forces can act with or without objects touching.

The different kinds of force

Science

What forces do

Measuring forces

Using force arrows

Balanced and unbalanced forces

Friction

Reducing friction: practical

Reducing friction: analysis

Energy

Transferring energy

In the Hidden forces unit, they will build on this knowledge to learn about turning forces, forces that hold objects on a surface, and those that make some objects float.

In primary science, pupils learnt that air resistance, water resistance and friction push back against moving objects. 

This unit focuses on quantifying and comparing energy transfers in different processes, such as motion changes, electrical circuits, and fuel burning. It examines forces as interactions between objects, using diagrams and measurements, including contact and non-contact forces.

Forces

A force that only acts when objects are touching.

A force that can act whether objects are touching or not.

Match the correct definitions to the keywords.

The gravitational force from a star, planet or moon.

The force of one surface rubbing/gripping another surface.

Match up each kind of force with its definition.

Gravitational forces are the attraction of Earth.

Gravitational forces only act when objects are touching Earth’s surface.

Gravitational forces only act when objects are not touching Earth’s surface.

Gravitational forces act whether objects are touching Earth’s surface or not.

Which is the best explanation for why gravitational forces are non-contact forces?

Which force does not act on this boat? The boat is not moving.

The pull force of the person on the rope.

The friction force of the ground on the sled.

The tension force of the rope on the sled.

The gravitational force of Earth on the sled.

Look at the picture. Which of the following forces does not act on the moving sled?

Which kind of force pulls objects down towards Earth's surface?

The force that acts when surfaces grip or rub against each other is called {{}}.

Which is the correct name for the force that makes things float in water?

What do forces do? Forces cause objects to {{}} their speed, direction of motion or shape.

The force of one magnet attracting an iron nail.

The force of one magnet repelling another magnet.

The gravitational force of planet Earth on a ball thrown in the air.

The force exerted by a foot kicking a football.

Which of these forces only acts when the two objects are touching?

What is the best way of describing this force?

The different kinds of force

Lesson outcome