Question

Give reasons for the following:

(a) When we want to warm a liquid, we should warm it from below.
(b) Places close to the sea have a moderate temperature.

Answer 1

a) When we heat water from below, water at the bottom of the vessel becomes hot and rises up as it is lighter than cold water. It carries heat energy along with it, thus heating all the water in the vessel.
b) Land heats up faster during the day causing sea breeze and when the lands cool down faster at night, it causes land breeze. Thus, convection helps to maintain moderate temperature at places near the sea.