Sneezing requires an increase in pressure of the air in the lungs;

a typical sneeze might result in an extra pressure of \(7.0 \mathrm{kPa}\). Estimate how much force this exerts on the diaphragm, the large muscle at the bottom of the ribcage.

Long-distance balloon flights are usually made using a hot-airballoon/helium-balloon hybrid. The balloon has a sealed, flexible chamber of helium gas that expands or contracts to keep the helium pressure approximately equal to the air pressure outside. The helium chamber sits on top of an open (that is, air can enter or leave), constant-volume chamber of propane-heated air. Assume that the hot air and the helium are kept at a constant temperature by burning propane.