Ear "popping" is an unpleasant phenomenon sometimes experienced when a change in pressure occurs, for example in a fastmoving elevator or in an airplane. If you are in a two-seater airplane at \(3000 \mathrm{~m}\) and a descent of \(100 \mathrm{~m}\) causes your ears to "pop," what is the pressure change that your ears "pop" at, in millimeters of mercury? If the airplane now rises to \(8000 \mathrm{~m}\) and again begins descending, how far will the airplane descend before your ears "pop" again? Assume a U.S. Standard Atmosphere.