Sledding, a fun activity to do over the winter, applies to Newtons laws of motion. Newton's First Law of Motion, the Law of Inertia, states that an object will not change unless it is acted on by an outside force. This means that an object at rest will stay at rest until a force causes it to move. Additionally, an object in motion will stay in motion until a force stops it. When you are on top of a hill, there is no force pushing on you therefore you don't move. When you go down the hill, the force of gravity is on you therefore you have some velocity. When get to the bottom, the force of friction slows you down until you stop. Additionally, the acceleration of the sled is affected by the frictional force of the snow to the sled.