Session 2: Let’s experience Forces

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At this age, primary school, we want that the pupils experience with their bodies that the effect of forces are directional, vary in intensity (and are applied at one point).

Objective1: Experience the impact of forces using different angles

Objective2: Explain that forces can be applied in different direction

Material

• 3 strong ropes And/Or 3  fitness elastics

• heavy bucket (15 kg of sand for example)

• chalk

• compass

• et square

• Gloves (for pulling ropes)

Main questions to be asked:

• Do you think that force has a direction? 

Introduction/Starters

• Give your students a rope and then ask them to organise themselves and to pull.

• Discuss with them what happened?

• Do the same with 3 groups and three ropes attached in the middle. What is the difference?

Main activities

Optional mathematical experiments: how to attach 3 ropes around a bucket at different angles?

Some ideas for experiments are explained below, but you may have other ideas:

A. For young children:

The concept of angle has not been introduced in the curriculum for your group.

For 120º, you take the perimeter of the bucket with a rope, you divide it in three and divide the rope in three equal parts or possibly you ask them to find a way of dividing three parts.

For 180º and two times 90º degrees you can again use a rope passing by the centre of the bucket and then take a set square to adjust a right angle;

B. For older children:

The concept of angle is known:

There are plenty of ways to do this. One of them consists in drawing on the floor, dividing the angle like a piece of cake, ….. It can be checked with a rope like the experiments for the younger children…

Please feel free concerning the time you want to dedicate to this parallel activity and to treat the mathematical aspects up to the point you want to reach with your students. We propose some starting ideas, but there are plenty of alternatives that you might enjoy testing with your class.

Conclusion/Plenary

Snowball:  ask pupils to write down one thing they learnt about forces (give them 30 seconds), then ask pupils to form pairs and write down three things they have learnt about forces (give them 1 minute), then ask the pupils to sit in groups of four and let them write six things they have learnt about forces (give them 2 minutes).  Each group of four feeds things back to the rest of the class.

Please feel free concerning the time you want to dedicate to this parallel activity and to treat the mathematical aspects up to the point you want to reach with your students. We propose some starting ideas, but there are plenty of alternatives that you might enjoy testing with your class.

A. Apply constant forces in different directions

• Divide the students in three groups.Mount the bucket with the 3 ropes attached at an angle of 120º. Then ask them to pull the rope and find a way to stabilise the bucket. Ask them to draw their representation of the forces on the floor with the chalk.

• Do the same but with the two ropes forming an angle of 180º, and the last one forming  90º. Ask them to draw their representation of the forces on the floor with the chalk, in a different colour.

• Do the same, but now each of the groups are placed next to each other. Ask them to draw their representation of the forces on the floor with the chalk, in a different color. Discuss with them their conclusions.

B. Apply different forces in different directions

• Put one student pulling two of the ropes, then all the other students at one end.
• Apply the same procedure as for images above
• Discuss the difference with the students