Acceleration of Gravity Lab

The purpose of this lab was to determine the acceleration of gravity for a free falling object, and to become literate with the equipment that was use to collect the data. We were shown how to set up the equipment, and how to accurately throw the object so the sound waves given off by the motion detector capture the motion of object as it is thrown up and falls back down.

We first set up the software and opened up the program that would be recording the motion of the ball. We were to throw the ball above the motion detector and let it fall back down on to the motion detector. We practiced for a couple tries and then started recording our trials until we had a position vs. time graph and a velocity vs. time graph that had the least amount of error which was these:

The velocity vs. time graph gave us a parabola because as the ball moved away from the motion detector, it was increasing till it came to a stop which would be the maximum of the parabola, and then the ball started to fall back down towards the motion detector which would mean it was decreasing. We were able to find the values of a, b, and c by using the quadratic formula:

x=At^2+Bt=C

The quadratic formula gave us the value of A(4.94) which we multiplied by 2 to give us our measured acceleration of gravity that came out to 9.88m/s^2. We then calculated the percent error by using this equation:

Percent Error= (measured-actual/actual)*100

The percent error that the formula was .816%, so our calculation wasn't that much off.

For the velocity vs. time graph we found the values of m and b using a linear fit to find the slope that would give us our measured acceleration of gravity which was 10.2m/s^2. We used the same function as the other graph to find the percent error which was 4.082%. The velocity versus time graph was also not far from being the actual accepted value of 9.8m/s^2 for the acceleration of gravity.