NSW Syllabuses

# STEM Stage 2 - Activity 5

### Magnetic movements

#### Description of activity

Students investigate the effects of magnetism. They design and make shoes or a device for a toy, which will enable the toy to move around, walk up a wall or hover.

This activity could take two hours:

• approximately one hour for exploration of the properties of magnetism
• approximately half hour to undertake a design process
• approximately half hour to make and test the design

#### Context

Students have been investigating magnetism. They define a force as a push, a pull or a twist. Students know that forces affect the movement of objects and that there are contact forces, eg friction and non-contact forces, eg gravity. Magnetism is a non-contact force.

Superheroes are able to walk up walls, hover and jump. Could it be their shoes that help them achieve these feats?

#### Outcomes

Skills

ST2-4WS investigates their questions and predictions by analysing collected data, suggesting explanations for their findings, and communicating and reflecting on the processes undertaken
ST2-5WT applies a design process and uses a range of tools, equipment, materials and techniques to produce solutions that address specific design criteria
MA1-1WM describes mathematical situations and methods using everyday and some mathematical language, actions, materials, diagrams and symbols
MA1-2WM uses objects, diagrams and technology to explore mathematical problems

Knowledge and understanding

ST2-7PW describes everyday interactions between objects that result from contact and non-contact forces
ST2-13MW identifies the physical properties of natural and processed materials, and how these properties influence their use
ST2-16P describes how products are designed and produced, and the ways people use them

#### Resources

• A variety of magnets, of different shape and strength
• Two bar magnets per group
• A variety of materials to test for magnetic properties including (but not only) a number of different metals, eg copper, aluminium, tin, brass, paperclips and iron
• Dolls or teddy bears for which shoes can be made
• Materials to make shoes/foot coverings

#### Work, health and safety

Check relevant Work, health and safety guidelines.

Note: Avoid using rare earth magnets for this activity.

#### Evidence of work for assessment purposes

• Written summary of the properties of magnets
• Labelled diagram of the magnetic shoe/device design with any modifications
• Labelled photograph or video of the toy using the shoes/device and either moving, walking up a wall or hovering

#### STEM teaching and learning activities

• Students explore the properties of magnets:
• Which substances are attracted to magnets?
• What happens when two magnets come close to each other?
• How can we measure the strength of a magnet?
• Students design a pair of shoes or device that will enable their toy to walk up a wall, hover or jump.
• Students determine whether their design requires magnetic attraction or repulsion.
• Students make and test their design.
• Students determine how to best record their findings and submit their evidence.

#### Vocabulary list

Attract – to bring closer together (attraction, n.)
Field– the area around a magnet that is affected by the magnet
Force – a push, pull or a twist
Pole – one of the two ends of a magnet
Repel – to move further apart (repulsion, n.)

#### Key inquiry questions

Is there a difference in the force of the magnet at different regions along the magnet?
A bar magnet or horseshoe magnet exerts a greater force at the ends of the magnet than in the middle region. A button magnet exerts greater force at the top and bottom of the magnet, rather than at the circumference. The ends of the magnet are called poles.The poles have been named ‘North’ and ‘South’ because of the way they are attracted to the northern magnetic pole of the earth.

How can you measure strength of the magnet?
Try placing a paperclip at the end (poles) of the magnet. How many paperclips can you place end to end? Is this number the same for all the magnets you test?
Try placing a paperclip in the middle region of the magnet. What differences do you notice?

What happens when you place the end of one magnet close to the end of another?
Sometimes the poles will be attracted to each other and sometimes they will repel each other. The rule is that like poles repel and opposite poles attract. Your magnets may have the label ‘N’ (for north) on one end and ‘S’ (for south) on the other. If N and S are placed near to each other they will attract each other. If N is placed close to another N or S close to another S, the magnets will repel each other.

The following statements outline some common preconceived ideas that many students hold, which are scientifically inaccurate and may impede student understanding.

All metals are magnetic
Only metals containing iron, nickel or cobalt are magnetic. All other substances are non-magnetic.

Bigger magnets are stronger magnets
The magnetic force depends on the composition of the magnet, the way it was magnetised and the arrangements of particles; not on the size of the magnet itself.

### Support materials

Teacher references

Student resources

#### Adjustments for the diversity of learners

Measure the forces of attraction and repulsion. To measure the force of attraction, students could place one magnet on zero, on a ruler, and place the other magnet progressively further away, recording at which point the attraction is no longer there. This could be measured in 5mm increments. As the attraction gets weaker students could be encouraged to increase the gap by 1mm for a more accurate measurement. Students collect results in a table. Groups compare results.

Observe the magnetic field around a magnet.
This can be done by placing the magnet under a sheet of paper and sprinkle iron filings gently over the magnet. You can also do this with two magnets to show the forces of attraction and repulsion.
Tip: Iron filings are difficult to remove from magnets. Consider putting each magnet in a sealed, ziplock plastic bag.