ANSWER TO QUESTION 1:
(a) The water enters the bath through the plug hole and fills it to a level of 10 cms; the water flow then ceases.
(b) The water now begins to fill the bath and rises to the level whereby the pressure is such that the rate at which water flows out through the plug hole equals the rate at which water is coming in through the tap. At this point the water level remains constant (this is how the overflow works when the plug is in the plug hole) i.e. a steady state is reached.
(c) The water level now drops until a height of 10 cms is again reached as in (a).
Question 2: In terms of heat (rather than water) how are:
represented in this analogy?