Lesson plan: Use the force

Song Bank link

Use the force (words and music by Jenny Beeching)

Subject links 

• Science QCA Unit 4E: Friction 

Duration 

45 mins - 1 hour

Learning Objectives

Children will learn:

• about friction as a force that slows moving objects and may prevent objects from starting to move;

• that when objects are pushed or pulled, an opposing pull or push can be felt.
  
  

Resources

• Use the force audio tracks and lyrics

• 2kg weights (one per group)

• Force meters (one per group)

• Carpet tiles (one per group)

• Sheets of sandpaper (one per group)

• Trays of sand (one per group)

• Trays of marbles (one per group)

• A tray of ice
  
  

 Introduction

• Display the lyrics on the IWB and listen to the audio track, encouraging children to join in where they can.

• Revise Year 2 work (QCA Unit 2E: Forces and movement) by asking children to highlight all of the ‘force’ words, eg. move, kick, pull, push.

• If the words ‘gravity’ and ‘friction’ have not featured yet, introduce them briefly, explaining that they are important ‘force’ words, and will be looked at in more detail later.
  
  

Main Activity

• Show two identical 2kg weights and ask children which would be the easiest to pull across the table.

• Demonstrate how a force meter (or a Newton meter) can be used to measure the force needed to pull the weight along the table top. Ask a child to examine the scale on the force meter, read it aloud, and make a note on the flipchart or whiteboard.

• Attach the force meter to the second weight. Before pulling the weight along, place the tray of ice underneath it. Point out that you are pulling it along in exactly the same manner as before – the only change is the surface on the table.

• Again, ask a child to check the reading on the force meter.

• Lead a whole-class discussion on this: why is there a difference? What is causing the difference? What different surfaces do the children think will make it easier or harder to pull the weight? Children should be clear that friction is a force between two sliding surfaces (or surfaces which are trying to slide), and that this force slows down a moving object.
  
  

Independent Activity

• In groups, children measure the force required to pull a 2kg weight table top (as in the main activity). Then they predict and then measure what will happen when using other surfaces: a tray of sand, a carpet tile, sandpaper, a tray of marbles, etc.

• They should record their findings in a simple chart.
  
  

Differentiation

Support

• Mixed ability groupings.

• Use of visual prompts; key words displayed.

Extension

• Ask children to note down how they ensured a fair test.
  
  

Plenary

• How does friction affect the force required to pull an object? (More friction means more force required.)

• How is friction increased and reduced? (Changing the smoothness of one or both surfaces: smoother means less friction.)

• How might a lubricant (eg. oil, grease) have affected the friction? (It would have reduced the amount of friction.)
  
  

Assessment for learning

• Describe and explain why it is more dangerous to drive on icy roads than on dry roads?

• Suggest when friction is useful (eg. grips on shoes or tyres) and when it is not (eg. skis)?
  
  

Next steps

• Move onto water resistance and air resistance – both are types of friction and, as such, are trying to slow down an object moving through them.
  
  

Differentiated success criteria

All children will:

• Understand that friction is a force; carry out a fair test on different surfaces for the effects of friction; predict and then measure the force required to pull an object across these surfaces; observe that surface texture affects the amount of friction.

Some children will:

• Understand that friction resists the movement of one surface against another; explain the factors in place to ensure a fair test; compare predictions with results; and explain how surface texture affects the amount of friction.

A few children will:

• Describe and explain situations in which friction is desirable and detrimental.