Gravity - the enemy of the high-jumper, and the diver’s friend. Find out how the sport of diving relies on gravity, and why a diver seems lighter in water than on land.

If you teach primary science, see the headings below to find out how to use this resource:

Skill development

Children will develop their working scientifically skills by:

  • Asking their own questions about scientific phenomena.
  • Using appropriate scientific language and ideas to explain, evaluate and communicate their methods and findings.
  • Planning different types of scientific enquiries to answer questions, including recognising and controlling variables where necessary.

Learning outcomes

Children will:

  • Explain that unsupported objects fall towards the Earth because of the force of gravity acting between the Earth and the object.
  • Identify the effects of air resistance, water resistance and friction on a moving object.

Concepts supported

Children will learn:

  • That weight and mass are different things – mass is how much of an object there is, weight is a measure of the force acting upon the object.
  • Where friction, air resistance and water resistance are encountered in everyday life and how they can be useful.
  • That objects are not lighter in water but there is upthrust from the water making the object appear lighter.

Suggested activity use

This activity could be used as an introduction to forces, particularly gravity, and to air resistance and water resistance. The activity will stimulate discussion and questioning, possibly leading towards a child-initiated investigation around exploring one of these factors.

Alternatively, it could be used as a piece of group work to check understanding about previously taught concepts. You might like to use this as a Guided Reading resource, where children can listen to or read the text and use comprehension skills to help identify key information from the text and answer questions.

Practical considerations

If not carefully explained, children may develop or reinforce the misconceptions that weight is how heavy an object is, and that objects are lighter on the moon and as a result they float.

This resource is designed to provide background information or an introduction to the topic; children should be encouraged to test forces in a practical way if possible.