Question

would you like to cool a bucket of water more efficiently by placing it on ice or by placing ice on it? Give reasons for your answer.

Answer 1

The water can be cooled by placing ice in it. If you place bucket of water on ice the ice will gain energy from the surrounding and melts. But if you place ice in water the ice is in direct contact with water. The ice melts by taking energy from water present in bucket. Here water is losing some energy so it becomes cool. 

Answer 2

I would like to cool bucket by placing ice in it as ice will start melting in bucket at it's temperature and the coolness of ice will be transferred to th water kept in bucket . whereas if we will put bucket on ice it will take much time and ice cubes