Answer the following:
(1) A glass of water has an ice cube floating in water. The water level just touches the rim of the glass. Will the water overflow when the ice melts? Give reasons.
(2) A block of plastic is released under water. Will it sink or come up to the surface of water? Give reasons.
A block of plastic released under water come up to the surface of water because___________.
Why does a block of plastic released under water come up to the surface of water?