Force Jump Shot

This project has been changed and will now be done by Brian Moore, John White, and Steven Delaney.
7th hour
We are going to analyze a basketball free throw shot.  We will test from different distances to see if it affects the speed or acceleration needed for the ball to reach the net.

The supplies we need are:
    a camera
    a basketball
    a professional basketball player (due to the unavailability of this, we will just use John White instead)
    the 2.5 meter pole (for video analysis)
    the use of the gym  
    force plate



The first test will be 1.5 meters in front of the free throw line.
The second test will be at the free throw line.
The third test will be at the three point line.
For each shot, we will use the force plate to measure the amount of force for several trials of each and then average the data of the trials for a final result.

We will then use video analysis to find the velocity and acceleration. 
In order to ensure accuracy, we will take three trials and makes sure the data is consistent.
We will then analyze the data to see how the different distances affect those variables.

     mass:  The first thing measured was the mass of the ball, which was .6 kg.
   3 Point line  free throw line  close to basket
 velocity  15.07 m/s  13.25 m/s  12.92 m/s
 acceleration  10.48 m/s2  6.954m/s2  5.984m/s2
force applied  6.288 N  4.1724 N  3.5904 N
 impluse  1.2414  1.6814  1.8216
 momentum  9.042  7.95  7.752
 This data is also represented in the attached graphs, which have video with them.
    The data shows, as we would expect, that acceleration and velocity both increase when the distance is increased.  The relationship could have been expected since more speed is needed in order to propel the ball a greater distance and a higher acceleration would be needed in order to get the ball to a higher velocity in the same amount of time.  In other words, John's shots all took the same amount of time to throw the ball, but he had to accelerate more from farther away in order to get the ball to move faster.  Using the mass and acceleration, we were able to calculate force for the acceleration of the ball.  The applied force was also greater for the longer distances because the ball was traveling faster and therefor had much more energy.  By multiplying force by the time it took to accelerate the ball, we can find the impluse and we can find momentum by multiplying velocity by mass.  The momentum was greater because the velocity increased while the mass stayed the same.  The impulse however, was less for the farther distances, probably because the ball bounced back from the backboard faster than the closer shots. 
     Although we cannot find the exact work that was done on the ball without the use of calculus, we can use the horizontal distance to find an approximation.  Work is equal to force times distance and figuring that a three point line is 6m from the net, we can find work done for all three distances. 
 3 point line  free throw line  close to net (3m)
 37.728J  18.7758J  10.7712J
As we could assume, more work was done on the ball from a farther distance.  When the ball hit the net, the forces would push towards the backboard and in response, the backboard pushes back, sending the ball either into the net or back at the shooter.  Also, gravity is constantly applying a negative acceleration to the ball in the downwards direction.
    Although our experiment yeilded no surprises, it was not a failure.  Finding what you might expect to find is still a result and it still allowed us to apply physics to sports.  As the distance increases, velocity and acceleration must both also increase.  The force and work done on the ball increase as well.  The only variable that decreased was impulse because the ball had a faster rebound.  And although our project did not yield exciting results, we can still make one assertion clear.  John White was able to throw a basketball at 15 m/s and thats FASTER THAN A CHAINSAW.  But not really.

Steve Dickie,
May 18, 2009, 6:51 PM
Steve Dickie,
May 18, 2009, 6:50 PM
Steve Dickie,
May 18, 2009, 6:50 PM