A Boeing 747 weighs around 750,000 pounds, so how does it manage to get off the ground? It’s all thanks to a force called lift and something you may be familiar with from other AstroCamp videos: Bernoulli’s Principle.
Lift is just the name for the force pushing an object up into the air, but Bernoulli’s Principle is a little more involved. It states that whenever a flowing substance like air increases in speed, the pressure inside the flowing portion decreases. This means that if the air flowing along one side of a surface is moving faster than on the other side, there’s higher pressure on one side, pushing the surface. We can see that with Lin’s sheet of paper; blowing on only the top side causes the now higher pressure below to push up on the paper, generating lift.
The same concept applies with the wings of a 747, though with one important difference: there’s airflow along both sides of the wing. However, airplane wings are designed to provide some air resistance along the underside, so the air moving along the top is still flowing faster, generating lift.