Question

(a) Radius of a bubble at the bottom of the tank shown below was found to be 1 cm, then find the radius of
the bubble at the surface of water considering the temperature at the surface & bottom being same.
Water
10.336 m
(b) If absolute temperature at the surface is 4 times that at the bottom, then find radius of bubble at the
surface.
​

Answer 1

The radius of the bubble is r1 =  3√( 1 + h ρ  g)

Explanation:

• P1 = 1 atm at surface
• P2 = pressure at the bottom
• V1 = Volume at the surface
• d = depth of the lake
• ρ = density of water

If the temperature is the same in both cases then

P1V1 = P2V2

V1 = (1 + h ρ  g)V2

V1 = (1 + h ρ  g) 4/3 πr^(3)^2

V1 = (1 + h ρ  g) 4/3 πr^(1)^3

4/3 πr^(1)^3 = 4/3 π(1 + h ρ  g)

r1 =  3√( 1 + h ρ  g)

Answer 2

Answer:

this is not correct

answer. this person copied from toppr

correct answer is 2