Question

what is the Formula for Projectile Motion?

Answer 1

There are several equations for Projectile motion depending on what your known values are, I refer you to the wikipedia page http://en.wikipedia.org/wiki/Projectile_motion since I must run off to lecture.

Answer 2

There are two equations, but they are really both special cases of the same general kinematics equation. Projectile motion (assuming parabolic trajectory and not elliptical satellite motion) consists of constant velocity in the horizontal and constant acceleration in the vertical.

x - x0 = vx(t)
y - y0 = vy(t) - (g/2)(t)^2
g~9.81m/s^2 near Earth.