Its scary to think about this, especially before a big flight down the coast, but honestly, how do planes fly? How is this big machine with tons of people, weighing literally tons, floating across the sky above the clouds? Well, I don't know either, but there is always physics to be found! Think about when you land in a plane and you get jolted back into your seat and can barely sit forwards until the plane actually slows down. Newtons law can come into play here. Because the plane is using the little "blades" on its wings to stop the plane and that creates a force to decrease the velocity at such a high rate, your body wants to stay where it is and not move but the lane wants you to continue forwards with it. You can't sit forwards because the planes force is so large it is withholding you to your seat back. You are jolted backwards until the negative acceleration is lessened and the planes force is less. This idea is the same as in trains, subway systems or cars when you are standing or sitting and the vehicle is trying to stop but your body doesn't want to go with it, it wants to stay where it is but instead you are pushed back into your seat or forced to hold on you you don't fall (like in the subway). Make sure you hold on tight!