Forces at a Distance

The Big Idea

The big idea of forces acting at a distance is that some forces can act between objects that are a distance apart.

To make the most of the idea, pupils need hands-on experience of attraction and repulsion. Magnets and charged balloons (rub inflated balloons on a woolen jumper) are excellent for this.

The problem with gravity, is that it it too weak to do experiments on unless the masses are enormous. On Earth, we have to use the Earth as one of our masses.

Misconceptions:

  • Many pupils believe there is no gravity in space. There is gravity, otherwise planets would fly away from the Sun and moons from their planets. We couldn’t have orbits without gravity.

  • Many pupils see falling as ‘natural’ and not requiring an explanation.

  • Many pupils think that all metals are magnetic, but only iron, cobalt and nickel are magnetic. Steel is also magnetic because it contain iron.

  • Many pupils think that gravity (and other forces which act at a distance) only exist then the objects are free to move.


Magnetism

The force between two magnets, or one magnet and a magnetic material such as iron.

Electrostatic Force

The force between two charged objects. You can charge objects by rubbing them - e.g. balloons rubbed on a jumper or hair.

Gravity

The force between two objects with mass.

EYFS and KS1

Pupils should experience magnets attracting and repelling and be able to describe the forces they feel. They should experience charged balloons to see them attract hair, small pieces of paper and walls.

Pupils may learn that the Moon and other planets in space also have gravity, but this might be stronger or weaker than on Earth (this could be taught through small world play).

Pupils should know that gravity pulls to the centre of the Earth (which is why people in Australia don’t fall off).

Pupils should learn that there are different types of metal and their names.

LKS2

Pupils should experience attraction and repulsion with magnets. They can test magnetic materials.

Pupils should learn that gravity holds planets in their orbits. They may learn the story of Newton sitting under the apple tree and realising that the gravity which pulls the apple to the ground is the same force that holds the Earth to the Sun and the Moon to the Earth.

UKS2

Pupils should understand that orbits happen because of gravity.

The force of attraction or repulsion gets weaker in non-contact forces the further apart the objects are.

Pupils should be able to compare and contrast magnetic force, electrostatic force and gravitational force.

KS3

Pupils will calculate the weight of objects using the gravitational field strength.