Q: A plane is flying horizontal to the ground with uniform velocity Vo. A stone is thrown at it with velocity V1 and angle alpha to the horizontal. If the stone hit the plane, at what height is it flying? The simple equations of uniform acceleration are available to me. We obviously have to equate x coordinate of plane during collision = x cooridinate of stone during collision y coordinate of plane during collision = y coordinate of ston during collision. I have attached an image of how I percieve this question. Sorry for the crappy drawing. Anyway, my question is how to write the equations of motion for the plane and stone. Thank you.