Jabulani+-+Real+vs+Fake

Group Members: Taso, Simone

Which ball, the real or fake, has a greater height when bounced from the same height?

VS


 * __Goal:__** **To figure out the which ball bounces higher.** Since both of us are soccer players we would like to test to see which ball is better to play with. This test will give us an idea of which ball will be easier to shoot or pass while in a real game situation.

__Procedure:__ We get both balls. We make sure the balls are of equal mass. We get to some height above the ground. (Pit) The height has to be equal for both balls. We measure the height of the drop. We drop the first ball and measure how high the ball bounces on a meter stick. Then we drop the second ball and measure how high the ball bounces. Then we will calculate which ball has a greater velocity when going down.

__Data:__ Pit height: 356.5 cm Jabulani replica bounce height: T1: 231 cm, T2: 234 cm, T3: 231 cm Real Jabulani bounce height: T1: 248 cm, T2: 246 cm, T3: 249 cm

__Conclusion:__

Our claim is that the real Jabulani ball bounced higher than the replica. Our evidence that the real ball bounced higher is in our three trials, the Real Jabulani ball bounced higher in each trial that we did. Our highest trial for the real ball was 249 cm and the lowest was 246 cm. Our highest trial of the replica ball was 234 cm, and the lowest was 231 cm. Although in a real life situation the balls will not be pumped to an equal PSI or they could also not be massed the same. Our possible sources of error are that, we tested two different days, the balls could have deflated a bit before testing them again that second day. Another source of error is that if the thrower of the ball (Simone) threw the ball up a little bit before dropping it.

Which ball, real or fake, has less air resistance?


 * __Goal 2:__** **Figure out which ball has less air resistance.** Again, because we are soccer players, we would like an advantage on the soccer field because of knowing how a ball travels in the air. The way the ball goes against the win determines which ball can fly faster, which could also help in a real game situation.

__Procedure:__ Continuing on from last goal... Time how long it takes the ball to drop. See which ball was the first one to hit the ground. Count how many times the ball bounces.

__Data:__ Pit height: 356.5 Time to hit the ground (Replica ball): .61 seconds Time to hit the ground (Real ball): .54 seconds Bounces (Replica ball): 10 bounces Bounces (Real ball): 12 bounces media type="youtube" key="zJO3-0RUx9c" height="315" width="420" media type="youtube" key="dlm72qTxvqo" height="315" width="420"

__Conclusion:__

Our claim is that the real Jabulani ball has less air resistance. The air resistance against the ball causes it to go slower in air. We determined which ball has less by how many bounces each ball had and how long it took for the ball to hit the ground. The real Jabulani ball hit the ground in .54 seconds after dropped from the height of 356.5 cm. The fake Jabulani hit the ground in .61 seconds, which is slower than the real ball. The real Jabulani also bounced 12 times which is more than what the replica bounced (10 bounces). In a real life situation this is going to be the same. The real ball does not have seams, which is what slows down the replica ball. This is why the replica ball is slower, the seams slow down it's velocity,Our possible sources of error are that the ball could have deflated like in the experiment above, also the thrower could have lifted the ball a little higher or dropped it a little lower than the actual height.