Procedure
For this lab, two students will form a team. The first student will use a stop watch to time the number of seconds between bounces while the second student will be the observer of how high the ball bounces. When the balls is dropped, the student with the stop watch listens for the sound of the first bounce, starts the stop watch, and then listens for the sound of the second bounce, when he immediately stops timing. The second student observes how high the ball bounces against the backdrop of the wall. To assist with calculating the height of the bounce, there are colored strips (green, orange, yellow pink), each 10cm wide numbered in 6 sets of four. Once the height and hang time for a bounce are recorded in the data chart, we repeat the process for a total of five trials.
The purpose of this lab is to experimentally calculate the acceleration due to gravity. If you examine each bounce, you will notice that the net vertical displacement equals zero. This tells us that the time for the ball to rise to its apex is exactly equal to the time it takes the ball to fall back to the ground. We also know that the instantaneous vertical velocity at the apex equals zero and the height of the apex.
Calculate the acceleration due to gravity by using the kinematics equation s = v _{o}t + ½at ^{2} and isolate the second half of the golf ball's bounce. Since you could only estimate the height of each apex to the nearest 0.05 meters, you should express the value for your experimental “g” to only two decimal places.

v_{o} = 0
 s = height of bounce

t = ½ (the total time on your stopwatch)


For each trial, place the results of your measurements of time and height as well as your calculated experimental value for “g” in the data table provided.

Data Table 

hang time between bounces

height of apex

experimental "g"

Trial 
(sec) 
(meters) 
(m/sec^{2})


Conclusions 
Refer to the following information for the next three questions.

A team may submit its data report online together. No papers need to be turned in to the oneway box for this lab.