ICSE Class 9 Answered

A block of wood is loaded with some heavy material, such that it just floats in a trough of water at room temperature. Explain, giving reason what change is likely to occur in state of flotation when (i) water is heated to (ii) Water is cooled at

Asked by Topperlearning User | 04 Jun, 2014, 01:23: PM

Expert Answer

(i) The block will sink in water at

Reason: On heating, the volume of water increases rapidly, as a result its density decreases. So, a greater volume of water is required to be displaced so as to balance the weight of the combination of wood and heavy material.

(ii) A part of block will rise above the surface of water.

Reason: Water has the maximum density at . Thus, the weight of water displaced at is more than than the weight of block. This in turn increases the upthrust and hence the block rises above the surface of water.