Sessumaru

So I have to use F=ma, as a base, right?

Hello! Gotta question here about Circular Motion... we all know that a = (v ^ 2) / r f = 1 / T and F = ma... Then how do I know which formula to use? For example, Calculate the force of gravity on a spacecraft 12,800km (2 earth radii) above the Earth's Surface if the mass is 1400kg?

...because the gravity is less on the high grounds than the lower grounds, which means that the air molecules are compactly held near the lower grounds that the higher grounds...did that help?