2.Falling Body Experiment - Acceleration of Gravity

The purpose of this lab is to determine the acceleration of gravity for a freely falling object and to gain experience using the computer as data collector.

We found the free fall acceleration of a rubber ball tossed into the air by collecting the ball position (x) vs time(t) data. Since the velocity of an object is equal to the slope of the x vs t, the computer also constructs the graph of v vs t because acceleration = ΔV/Δt. For this exercise we conducted 5 trials.

1.        We placed the motion detector in the floor with the basket for protection. Then we tossed the ball into the air until we got a position-time graph of a parabolic shape.

2.       We selected the data in the interval of the parabola we chose Analyze/curve fit and chose Quadratic.

3.       From the velocity vs time graph we found out the acceleration.

4.      Finally we calculate the percent difference for each of the trials.

 

Results from Falling Body Experiment
trial	g exp	% diff	g exp	% diff
1	-9.302		-9.785
2	-9.506		-9.61
3	-10.156		-10.62
4	-9.99		-10.06
5	-9.534		-10.1

 

Conclusion:

In this lab, we determine the gravity is close to 9.8m/s^2.
In order to get the most precise data, we did this experiment for many times and got the average data, which decrease the error accidental error. Our data is 3.18% varying from the actual, that mean this experiment can prove that the gravity for a freely falling object is close to 9.8m/s^2. Our errors are because of : Air resistance, The inevitable experimental error, because the equipment can't be exactly precise. The curve fit is an estimate, so our gravity is also an estimate value.

We also learned how to use Lab Pro interface, Logger Pro Software, motion detector and gained the experience using the computer as a data collector. We also worked as a team to gain and analysis the data. This experience may benefit us in the future.