when swimming you use physics in order to get from one place to another in a pool. you exert a force on the water and the water exerts a force back onto you which is why you are able to move in the pool. when diving you jump off the diving board and gravity is acting on you. if it wasn't you would be floating in space right about now. because of tis you make a splash when you hit water. the splash is caused by the force that you exert when you hit the water. als friction is applied to your body when youre in the air as well as air resistance.