A student investigated how the pressure in a diving pool varied with depth. He filled a
balloon with helium and tied it to the end of a long pole. Then he submerged the
balloon to various depths and observed the result. Which one of the following best
describes what happed to the balloon as it went deeper?
(a) The balloon got larger because the pressure of the water around it increased
compared with the pressure inside the balloon.
(b) The balloon got larger because the pressure of the water around it decreased
compared with the pressure inside the balloon.
(c) The balloon got smaller because the pressure of the water around it increased
compared with the pressure inside the balloon.
(d) The balloon got smaller because the pressure of the water around it decreased
compared with the pressure inside the balloon.