Hi

You say nothing about how much gas had already leaked out. Or is this assumed to be zero ?

You have that gas is leaking out with , so lets say the time variable is in minutes.

Call the amount of gas leaked out. Then:

Set if none had already out.

The gas forms a cylinder on the water.

This gives us: , since we are using SI-units here, that is calling 1mm = 0.001m .

To find the radius as a function of the amount of gas, interchange V for