Diving bell. A cylindrical diving bell, open at the bottom and closed at the top
ID: 1466858 • Letter: D
Question
Diving bell. A cylindrical diving bell, open at the bottom and closed at the top, is 4 m tall. Scientists fill the bell with air at the pressure of 1.0×105N/m2. The air pressure naturally increases by 1.0×105N/m2 for each 10 m that the bell is lowered below the surface of the water, without any interference from the scientists above. The amount of air inside the bell does not change. Part A If the bell is lowered 30 m below the ocean surface, how many meters of air space are left inside the bell?
Explanation / Answer
Taking your number to be 1.0×10^5 N/m2 lacking superscripts which is pretty much standard.
A water column 30m tall applies approximately 3 atmospheres of pressure so the pressure on the air in the tank has gone from
one atmosphere to four atmospheres so the fraction is 1/4th.
So the air space now is 4m*1/4 = 1 m