Why do you suppose that airplane windows are smaller than bus windows?
Solution 12E Step 1 : The buses usually travel on ground whereas the airplanes travel at above the ground level say 30,000 feet high The air in the higher altitudes are thin, which causes less air pressure The air pressure inside the plane has to be kept such that the passengers in plane can breath the same way on ground So there is high pressure of air inside the plane and lesser air pressure outside the airplane The tendency of the nature is to maintain equilibrium, if the airplane have bigger windows, air pressure inside the plane pushes the plane outward but since the air outside the plane is thin it does has very little pressure on the plane , this would make the airplanes expand Whereas the smaller windows helps to maintain the difference in the air pressure inside the plane and outside