Permanent magnets give a strong magnetic field for the motor.
Electromagnets need electricity to become magnetic.
Using iron instead of magnets reduces the motor's efficiency.
Lower efficiency means the car uses more battery power.
Strong magnets help the car start moving quickly and reach high speeds.
Scientists wanted to replace the permanent magnets with electromagnets or just iron.
But doing that makes the motor less efficient, harder to start, and slower.
Therefore, the cars still use rare earth magnets to keep performance high.
These magnets are made from special rocks found deep in the earth.
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