Circular motion one. Think about what keeps an object up after it is thrown. Once an object is thrown into the air, there is only the downward force of earth’s gravity that acts on the object. That does not mean that once an object is thrown in the air, it will fall instantly. What keeps that object up in the air is its velocity. The first of Newton's laws of motion states that an object’s inertia keeps it in motion, and since the object in the air has a velocity, it will tend to keep moving in that direction. A varying angular
Reduced-gravity aircraft the final third not at all." Vomiting is referred to as "ill". Scopolamine is often used as an antiemetic during reduced-gravity-aircraft training. Reduced-gravity aircraft A reduced-gravity aircraft is a type of fixed-wing aircraft that provides brief near-weightless environments for training astronauts, conducting research and making gravity-free movie shots. Versions of such airplanes were operated by the NASA Reduced Gravity Research Program. The unofficial nickname "vomit comet" became popular among those who experienced their operation. Parabolic flight as a way of simulating weightlessness was first proposed by the German aerospace engineer Fritz Haber and the German physicist Heinz Haber in 1950.