A helium-filled balloon released in the atmosphere will rise until
A) atmospheric pressure on the bottom of the balloon equals atmospheric pressure on the top of the balloon.
B) the pressure inside the balloon equals atmospheric pressure.
C) the balloon and surrounding air have equal densities.
D) all of these
E) none of these

Question

Quizplus · Accepted Answer

A helium-filled balloon rises due to the difference in density between the helium inside the balloon and the surrounding air. It will stop rising once it reaches an altitude where the density of the surrounding air equals the density of the helium inside the balloon, making buoyant force equal to the gravitational force acting on the balloon.

A Helium-Filled Balloon Released in the Atmosphere Will Rise Until