I am doing a fairly large projectile motion problem. I am trying to describe the act of throwing a ball from an elevated point at an upward angle into a lower point, while taking into account the affects of ball spin, air resistance, etc. First, I have a question about the act of throwing a ball. When you throw a ball, you form a lever with you elbow, so the motion of throwing the ball makes an arc. When you release the ball does the ball continue tha arc, or does it start moving with a vector magnitude when you release it? Next I have a question about my equations. The y-component of my vector forces at this point is: sin(a)Vn(m)-mg where a is the angular component of the vector, V is the magnitude of the vector, m is the mass of the object and g is gravity. The x-component is: cos(a)Vn(m). I don't know if my equation is right however, being that the result is going to be an arc, doesnt that mean that I would need to find some way to calculate the tangent line of the previous point in the arc to clculate the next point? I guess what I am asking is how to I take my x and y vector components, apply gravity to them and turn them into a singular equation for my arc? Also, I need to know how to do this because later on I need to apply air resistance, and the spin of the ball to the equations oh, also, because it forms an arc, does the ball have angular momentum? I don't think it does because it is just vector forces acting on the ball at this point, I understand that once I add spin it will, but the arc of a non-spinning ball only has linear momentum right?