Today in class we talked a lot about projectile motion.  This tennis ball is a good example of a projectile in everyday life.  We learned today that when you throw a ball, the x and y axises are independent.  I'll always be able to remember this through the Vegas rule: what happens on the x axis stays on the x axis, what happens on the y axis stays on the y axis.  I now know that if I had two tennis balls and I threw one to the side at the same time as I dropped the other one, both balls would land at the same time.  This is because of the Vegas rule, the x-axis does not affect the y-axis.  I also know that if I was ever on a train with a cannon, it would not be a good idea to shoot the cannon straight up in the air because the cannon ball would just land on the train.