Helium balloons are used regularly in scientific research. A typical balloon would reach an altitude of 40.0 km with an air density of 4.3*10^-3 kg/m^3. At this altitude the helium in the balloon would expand to 540000.0m^3. Find the buoyant force on the balloon.

Answer 1

Mass=540*10^3m^3 * 4.3*10^-3kg/m^3 =
2322 kg.

Fb = m*g = 2322kg * 9.8N/kg = 22,756 N.