Term 3 Topic 4 Elastic & Springs Copy

• Many vehicles are systems that use wheels and axles.
• Wheels and axles help vehicles to move more easily.

• Greet the learners.
• Show them your toy car/truck and push the toy across your desk.
• Ask learners why the car/truck can move forward.

Possible Answers:

It has tyres, wheels, an axle, elastic, you are pushing it.

• Ask learners what shape the wheels of the toy car are (round/circle).
• Ask them why they think the wheels need to be round.

Possible Answers:

If they were square, it would be bumpy when you push it.

If they were oval it wouldn’t turn smoothly:

• Show learners the picture of Egyptians pulling a huge stone block. You will find this picture on pg 53 of THUNDERBOLT KIDS.
• Ask learners why they put the blocks on round logs.

Possible Answers:

To move it more easily; to work together; because they can’t lift the block.

• Show learners the following simple demonstration:
  • - Place a stone on a piece of cardboard.
  • - Place the cardboard on a number of pencils.
  • - Now push the stone gently forward.
  • - Ask learners what they notice about the demonstration.

Possible Answers:

The pencils moved forward and in a circular movement when you pushed the stone; the pencils acted like wheels.

• Show Presentation 1, explaining as you go through it.
• Explain to learners that when we have to move a real heavy load, we have to use a great deal of force to push it, because of:
  Friction: A force that  resists the motion of the object on the ground.

Gravitational force:  Force that pulls the object to the ground.
This problem is solved through the uses of wheels and axles.

• Show Video Clip 1 (12.46 minutes). This video explains the functioning of simple machines (wheels and axles).

• Hand out Worksheet A and let learners complete it.
• Ensure that learners cut out neatly and safely, pasting and labelling their items correctly.

• Greet learners.
• Ask them to describe a wheelbarrow.
• Ask them to say why a wheelbarrow is useful.

Possible Answers:

It helps us carry things more easily; it moves heavy things.

• Show Presentation 2, explaining as you go through it.
• Show Video Clip 2 (12:46 minutes). 

In this video we learn how wheels and axles work.

• Hand out Worksheet B and ask learners to complete it.
• Learners will need to form groups of 4.

• Tell children that in the olden days, children often had to make their own toys.
• We don’t need any expensive things to make a toy car – we can even use a plastic cooldrink bottle.
• Show Video Clip 3 (3:38 minutes). 

The video shows how to make a toy car from a plastic bottle.

• Challenge learners to make their own toy cars and to come and show it to the class.
• If time permits, this activity can be done in class.
• Show Video Clip 4 (14:32 minutes). 

To make the car, learners will need:

• 4 toothpicks.
• 2 drinking straws.
• 4 bottle caps.
• rubber bands or loom bands.
• Modelling Clay for extra weight.
• Hot Glue Gun or other strong glue.
• Soldering iron.

• Learners complete Quiz 1.