Alright, so I know there will be a normal force pointing perpendicular to the surface and gravitational force, right? Gravitational force = mg But since normal force acts in "opposite direction to the gravitational force". Wouldn't normal force then cancel out the gravitational force? If it's so, wouldn't you just "fly" for a moment up, then come back? You'll come back because once you stop touching the ground, normal force would stop acting on you... If an object rests on the ground, then angle is zero cos(0) = 1.