A balloon is made of a material of surface tension and its inflation outlet (from where gas is filled in it) has small area . It is filled with a gas of density and takes a spherical shape of radius . When the gas is allowed to flow freely out of it, its radius changes from to (zero) in time . If the speed of gas coming out of the balloon depends on as and then:
- A
- B
- C
- D
Solution & Step-by-step Explanation
The excess pressure inside a spherical balloon is . By Bernoulli's principle, the velocity of the exiting gas is related to pressure as . Thus, , so . However, looking at the problem's flow, let's use dimensional analysis for .2. Dimensional Analysis for : Equating powers:
Time:
Mass:
Length: Usually, the rate of change of volume . Since , .
With , we get .
Integrating gives ..
Thus: .
Checking options, Option (3) fits and .