3. Explain why one side of the single magnet attracted the metal surface, but repelled the stack of magnets

Explained

Explanation:

one side of the single magnet attracted the metal surface, but repelled the stack of magnets because magnet's both poles try to attract by inducing opposite pole on the metal surface, but the pole closer to the metal is able to induce more magnetic character. so, attractive force due to this is more strong as the distance is also less as compared to the other pole.

Magnets have the property where opposite poles attract each other and same poles repel each other. The single magnet in this case repels the stack of magnets which means that the poles of the single magnet and stack of magnet are same.

Metals are not permanent magnets. Temporary magnetism can be induced in metal by bringing a magnet close to it. The poles of the metal surface will be such that it is attracted by the magnet.