Skydiving is a great activity for experiencing some key laws of physics.
Skydivers jump from planes flying high above the earth. Immediately, and in a rather dramatic way, they become keenly aware of the force of gravity. At a certain point, their parachutes open, giving them, on top of a tremendous feeling of relief, a sensation of deceleration caused by friction with the air, or drag. Below is additional information to help understand how this works, along with some historical notes. Two balls of different masses, but of similar shape and density that were released together hit the ground at the same time.