A force is a push or a pull. Forces can make objects change speed, change direction or change shape.

Water resistance is a type of friction force which acts between a liquid and the surface of an object.

In a comparative test, the thing that is being changed has labels, such as the types of materials.

A variable is something that can be changed, measured or kept the same in an investigation.

Water resistance: plan

Science

In this Forces and simple machines unit, pupils learn that air resistance, water resistance and friction push back against moving objects. In this Forces unit, pupils will build on this knowledge to accurately describe and explain the actions of forces in a range of situations.

In the Simple forces including magnets unit, pupils learnt to compare how things move on different surfaces. In this Forces including simple machines unit, pupils will build on this knowledge to identify the effects of air resistance, water resistance and friction, that act between moving surfaces

Forces including simple machines

Physical activity and equipment requiring safe use

Use of equipment that may require supervision for safety, e.g. scissors in KS1, needles, paint, knives, cooking.

Which of these is not a liquid at room temperature? 

{{}} is a force which acts to slow down or stop objects that are moving through liquid.

Scientists plan tests and control {{}} to investigate water resistance.

To help them understand how cars move on different surfaces.

To help them understand how planes move in the air.

To help them understand how boats move in water.

Why might scientists ask questions about water resistance? 

Water resistance acts in the {{}} direction to the moving object.

{{}} is the force which acts between a moving sledge and the snow, in the opposite direction to the movement.

Long thin shapes have less air {{}} because there is less area for air to bump into.

The total area taken up by all of its surfaces added together.

Match the object shape to the relative size of its surface area:

These shapes are all made with the same mass of sticky tack.  Which one of them has the greatest surface area?

If you want to fall through the air as slowly as possible you should __________ your surface area.

Content guidance

Risk assessment required - equipment

Adult supervision required

Introduction

What will you need for this lesson?

Are you ready to learn?

Equipment

Content guidance

Supervision

Worksheet