2.17 To test the magnetic force of a magnet on magnetic as wells

Natural sciences

Energy transfers and forces

Educator section

Memorandum

(a) What do you observe? The paper clip also moves upwards and remains hanging in the air under the magnet.

What happens? The paper clip falls back onto the bench.

(b) What happens? The paper clip retains its position in the air.

Conclusion: Magnets are able to attract magnetic materials through non-magnetic materials, but not through magnetic materials.

Explanation: A tin can is made of iron that is covered with a thin layer of tin.

Leaner section

Content

Activity 18: to test the magnetic force of a magnet on magnetic as wells as non-magnetic substances [lo 2.3]

(a) Tie one end of a length of sewing thread to a paper clip and use wonder glue / Prestik to secure the other end to your desk. Hold a bar magnet above the paper clip and lift it.

What do you observe? _________________________________________________

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Now place the lid of a tin can between the paper clip and the magnet.

There must be no contact between these objects.

What happens when you do this? _________________________________________

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(b) Repeat the procedure of 4(a), but insert a sheet of paper between the magnet and the paper clip.

What happens now? ____________________________________________________

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What deduction can you make from this? ___________________________________

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• Remember that paper is a non-magnetic material and the tin can lid is a magnetic material.
• Try to explain why the tin can lid is magnetic, while tin is not.

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5. a magnetic field

A magnet is surrounded by a magnetic field. This is the area around a magnet in which it can experience force. The earth must therefore be surrounded by a magnetic field, and this would mean that we are living in a magnetic field! What would happen if there were no magnetic field around the earth?

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We will now use iron filings to help us examine the magnetic field of a bar magnet.

Asessment

Learning Outcome 2: The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

Assessment Standard 2.3: We know this when the learner interprets information by identifying key ideas in text, finding patterns in recorded data, and making inferences from information in various forms (e.g. pictures, diagrams, text).