There is more and more snow that is falling from the sky and many people take the chance and go outside and go sledding. However what many people dont realize is that sledding involves alot of physics. For example, Newtons first law, says that an object in motion will not change unless acted upon by an outside force. In other words an object at rest will stay at rest until a force causes it to move and an object in motion will stay in motion until a force acts on it and causes it to stop. For example, it takes a pretty strong push to get you with your friend on the same sled moving, but once you get speed you'll keep going even at the bottom of the hill where the run flattens out. It takes much more force to stop you and your friend on the sled than to stop an empty sled.