The Physics of Basketball
The NBA playoffs are making the headlines all over. Every news channel, sports channel, and newspaper has a story about the big games. Everyone is making bets as to who will be the big champions. Will it be the defending champions, Los Angeles Lakers, or will it possibly be one of the underdogs. This is the most intensive time of year for basketball fans as they watch the teams battle out the game. Up and down the court, the turnovers, rebounds, fast breaks, and most of all the baskets make the games exciting. But have you ever wondered how these things happen? What enables the basketball to bounce, how does Kobe Bryant fly through the air, and why does the ball rotate backwards as it leaves a shooter’s hand and approaches the basket? These are all interesting questions and believe it or not they can all be answered with a discussion on physics. Whenever you watch a basketball game you are watching the “application of physics. It is very much at work in the game of basketball” (Hawkins).
One of the key pieces of equipment in the game is the basketball itself. The ability of the ball to bounce is entirely explained by physics. The law of conservation of energy says that the total energy of an isolated system does not change (Kirkpatrick, 131). When the ball comes in contact with the floor an elastic collision occurs in which the kinetic energy of the system is conserved. Two things determine the elasticity: the air pressure in the ball and the surface it is colliding with. The more pressure in the ball, the better the bounce and the greater elasticity. The energy will be stored in the compressed air inside the ball creating a greater bounce. “Air stores and returns energy more efficiently than the material the ball is made from” (Willis). When the ball is partially deflated there is little bounce upon colliding with a normal court floor. This happens because kinetic energy is not conserved. The energy is wasted in deforming the ball as it hits the surface creating an inelastic collision. For the best bounce you want a highly pressurized ball.
The other factor that determines the quality of the bounce is the surface that the ball is bounced on. The harder the surface the more elastic the collision will be creating a useful bounce. Why doesn’t a ball bounce very well off of a soft surface such as carpet? A soft surface will create an inelastic collision in which the energy is not conserved. A hard surface is also needed to produce an effective bounce.
In order to use your teammates while playing basketball, one must pass the ball to them. Most passes are hard and fast, but the impact of a hard pass can be lessened if caught appropriately. A ball coming at you has momentum. Momentum is equal to mass * velocity (mv) so if the ball is coming fast it will have more momentum. Since mass * velocity = force * time, then the total force or impact of the pass will be (mass*velocity) / time. From this equation we...