For one thing, the camera that C drops into a frame for you as default is in the corner of the universe, (so to speak.) If I am trying to get something accurate to a real life scene, then I move my camera so that it is directly looking in on the 'y' axis. That way all my measurements make sense to the camera as well as in my head. THEN I break the rules and place my camera where I want it to end up in the final animation, (usually a room flythrough.) Placing yuor camera in this direction should allow for a simple angle of velocity IN ONE DIRECTION to help your coin fall towards the camera. Hope this helps!