Grade 3 (age 8-9)

grade 3 Magnets and Magnetic Force

Magnets and Magnetic Force

A magnet has an N pole and an S pole, so opposite poles attract and like poles repel. The magnet on a fridge and the compass that points the way both use this force. The force is stronger up close and weaker farther away, and it pulls on iron, nickel, and cobalt. Change the gap between two magnets and the push and pull changes.

Poles of a Magnet

Distance Between Magnets30

🧲 Magnet Rules

①A magnet has N and S poles

②Different poles (N↔S) attract

③Same poles (N↔N, S↔S) repel

④This force is called magnetic force

Force Around a Magnet

💡 Distance and Magnetic Force

①Closer to magnet = stronger force

②Farther = weaker force

③Iron filings reveal the field

④Compass needles are magnets too

⑤The step 1 distance slider also changes this field picture

Summary

Key Magnet Law

Different poles → attract / Same poles → repel

N and S attract, N↔N or S↔S repel

Magnetic Force vs Distance

Closer → stronger / Farther → weaker

Force changes with distance

🎯 Key Points

①Magnet always has both N and S poles

②Different poles attract, same poles repel

③Closer = stronger

④Compass uses Earth magnetism for direction

⑤Magnets attract iron, nickel, cobalt. Properties of Materials compares metals

Examples and Unit Test

Example 1

If you bring the N pole of one magnet close to the S pole of another, what happens?

Different poles of magnets (N pole and S pole) attract each other.

So bringing an N pole and an S pole close makes them attract each other (attraction).

▸ They attract each other (attraction)

Different poles attract; like poles repel.

Example 2

If you face an N pole and an N pole and bring them closer and closer, what happens?

Like poles (N pole and N pole) repel each other (repulsion).

The force of a magnet is stronger when closer, so they push apart more strongly as they get closer.

▸ They repel, and push apart more strongly the closer they get

Like poles repel, and the magnetic force is stronger when closer.

Unit-test style

Which statement about magnets is correct?

①Like poles attract each other

②Different poles attract each other

③The force gets stronger as you move away from the magnet

④A magnet has only an N pole

⑤A magnet attracts plastic

▸ ② Different poles attract each other

A magnet attracts with different poles (N and S) and repels with like poles.

Like poles repel (①), the force is stronger closer to the magnet (③), a magnet has both N and S poles (④), and a magnet attracts iron, nickel, and cobalt (⑤).

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