Physics GCSE: Gravity on Earth and in space

Jon Chase explains that the mass of an object is constant but its weight depends on the gravitational force.

This force is higher on more massive planets and he would weigh more on Jupiter than on Earth.

Jon uses a fairground ride to simulate the feeling of lower and higher gravitational forces. He explains that gravity is the force that keeps spacecraft and moons in orbit around planets and planets around stars.

Astronauts in the International Space Station experience weightlessness because they are in orbit and constantly falling towards Earth.

This short film is from the BBC series, Space Science Bites.

Teacher Notes

Discuss the difference between mass and weight.

Students could compare the weight of 1 kg mass on different planets.

The class could give their own examples of feeling lighter or heavier and describe the forces involved.

Introduce the idea of gravitational force causing lighter objects to orbit heavier ones, perhaps using concept cartoons or true/false statements.

Curriculum Notes

This short film will be relevant for teaching physics.

This topic appears in OCR, Edexcel, AQA, WJEC KS4/GCSE in England and Wales, CCEA GCSE in Northern Ireland and SQA National 4/5 in Scotland.

More from Space Science Bites:

The life cycle of stars
Nuclear fusion in stars
The Big Bang and red shift
Spectroscopy and the composition of stars
Waves and communication