Diver Down 1

Suppose you have a 10-meter deep water tank and send a diver with a barometer to the bottom. What is the measured pressure?

A) A bit more than 1 atmosphere

B) About 2 atmospheres

C) About 3 atmospheres

D) About 10 atmospheres

E) Something else

Solution: B. Use the formula for pressure in a static fluid, P = P₀ + ρgd. We know the pressure at the surface of the water, the density of water, g, and the depth. P = 1.013E5 + 1000*9.8*10 ≈ 2E5 Pa ≈ 2 atm. So a good rule of thumb is that a 10 meter depth of water creates an additional pressure of 1 atm.