Fly Like An Eagle
The cruising altitude of most planes is about 10,000 meters above sea level where there is less air above the plane pushing down, so the air pressure is lower (about 20 kPa outside compared to about 100 kPa atmospheric pressure at sea level). To keep everyone comfortable inside the plane, the cabin is pressurized to about 75 kPa. The passenger doors on a 747 are about 1 meter wide by 2 meters tall.
If a metric ton is 1000 kg, to pull the door open at 10,000 meters is equivalent to moving how many metric tons? (the acceleration due to gravity can be approximated as 10 m/s2)