Acceleration due to Gravity - Measuring "g"

On a strip of waxed paper, the Behr freefall apparatus will produce a series of small dots showing the position of a freefalling "torpedo" at equal time intervals of 1/60 of a second. The drawing to the right shows the typical pattern of dots. Because the spacing between the dots increases as the torpedo moves down the paper, it is clear that the torpedo does not fall at a constant speed. There is a downward acceleration. However, it will require some analysis to determine the value of the acceleration and whether the acceleration is constant or changes as the torpedo falls.

Make a systematic selection of at least 10 dots between the top and bottom of the strip. Utilizing all of those dots, answer the following questions.

1. As determined within error, is the acceleration constant or not?

2. What is the average acceleration, g, for the 10-dot interval?

(Note that because of the torpedo is released manually, the time between the first and second dots us unknown. Hence, do not include the initial dot in the data.)

Discuss a plan of action with your partner before beginning measurements. The goal is to determine the acceleration due to gravity with as much accuracy as possible and to determine, within error, if g is truly a constant. You may use any appropriate calculations, averaging techniques, or graphs you wish, but your method should make use of all 10 points. The following should appear in your lab report.

1. Fully describe your method, clearly stating how your calculations correctly yield a value for g.
2. Estimate the error in your value of g based upon the accuracy of your measurements and/or consistency of individual calculations.
3. Include at least a plot of position vs time. You may wish to calculate g using graphical techniques. Of course, include any other graphs that you use.

It is advised that you discuss your plan of action with the instructor before proceeding. Good luck!