Sunday, September 14, 2008

momentum in pitching


I love watching my cousin play sports. I watch him play football and baseball for Iolani. In this picture Iolani is playing against Damien and JR is pitching. I wondered how pitchers could throw so fast and why they have that big wind up before they throw. I found out that the answer is related to physics. A net force is needed in order to accelerate an object and change its velocity and momentum. A change in momentum is called the impulse. A greater net force that acts on the object or the longer the net force is applied increases the impulse. The pitcher is like the net force that acts on the ball. In pitching, the momentum needs to be transfered from the pitcher to the ball. This causes the ball's velocity and momentum to change. The windup before the pitch is to create more momentum. This gives the ball more momentum and therefore it goes faster. It also helps if the pither is tall. JR is about 6ft which helps him to pitch the ball faster. Taller pitchers can make the ball go faster because they can apply the force for a longer period of time. The big windups that pitchers do before they throw the ball really does matter because it determines the momentum that is going to be transfered and the force that will act on the ball.

Sunday, September 7, 2008

physics in soccer




This weekend I played two soccer games. I was kicking around a soccerball afterward to work on some of my skills that I needed to improve on for the next games. I noticed that there was a physics concept in kicking the ball. It is related to Newton's first law. This law states that an object remains at rest or maintains a constant velocity unless a net force acts upon it. Before I kicked the ball, it didn't have any motion. It had a constant velocity of 0m/s. My foot is the exteral net force that acts upon the ball causing it to change its velocity. The ball will not move unless I kick it just like any object will stay at rest unless a net force acts upon it. It also works the other way too. An object that is in motion will stay in motion unless a net force acts upon it. So, the ball will roll at constant velocity (pretending there is no friction) unless my foot touches it . This weekend I realized that there was physics in a game as simple as soccer.