Thanks I looked it up on wikipedia and they have a nice simulation there. http://en.wikipedia.org/wiki/Newton%27s_cannonball http://en.wikipedia.org/wiki/Newto

Thanks I looked it up on wikipedia and they have a nice simulation there. http://en.wikipedia.org/wiki/Newton%27s_cannonball http://en.wikipedia.org/wiki/Newton%27s_cannonball I didn't understand the elliptical orbit at first and was writing a supplementary question here but as i did so the following explanation occurred to me. As it spirals outward it's no longer travelling at right angles to the force of gravity so now gravity exerts some force parallel and opposite to its direction of travel and starts to slow it down. It slows down at a rate greater than the required orbital speed does and eventually it's travelling at less than orbital speed and starts to travelling closer to earth again and now gravity starts to act to increase its speed because the ball is again not travelling perpendicular to the force of gravity but this time gravity's pull increases its speed. Now the ball's speed increases faster than the required orbital speed does until it exceeds orbital speed again. And so ad infinatum!