A small spherical monoatomic ideal gas bubble `(gamma=5//3)` is trapped inside a liquid of density `rho` (see figure). Assume that the bubble does not exchange any heat with the liquid. The bubble contains n moles of gas. The temperature of the gas when the bubble is at the bottom is `T_0`, the height of the liquid is H and the atmospheric pressure `P_0` (Neglect surface tension).

As the bubble moves upwards, besides the buyoncy force the following forces are acting on it

Options

A. Only the force of gravity
B. The force due to gravity and the force due to the pressure of the liquid
C. The force due to gravity, the force due to the pressure of the liquid and the force due to viscocity of the liquid
D. The force due to gravity and the force due to viscocity of the liquid

Answer

D

Explanation

(d) The forces acting besides buoyancy force are
(a) Force of gravity (vertically downwards)
(b) Viscous force (vertically downwards)
Foce due to pressure of the liquid is the buoyant force.