Swimming is a popular activity, both for recreation and competition. The physics of swimming involves an interaction of forces between the water and the swimmer. It is these forces which propel a swimmer through the water. When a person swims there are more forces acting upon them than you might think. First off a swimmer must push off the water in order to create thrusting force generally parrallel to the surface of the water, There is also the force of gravity on a person working in the y-direction however much of this force in cancelled out by the force of buoyancy. Lastly there is also some kinds of drag force That acts similar to a force of friction in the direction opposite of that the swimmer is moving in.