07-SEP-2016 Freefall Experiment to Calculate Gravity At 9.81 M/S^2

In this experiment we will drop a plumb bob down a sturdy column that stands 1.5 meters above the ground. With an electromagnet at the top to hold the plumb bob until we want to release it. When released it will travel down the column between to wires and a spark sensitive tape. A spark generator will mark the paper at intervals of 1/60th of a second and with this information we will make a distance vs time graph and a velocity vs time graph to calculate the rate of acceleration due to gravity.

After conducting the experiment we took the spark sensitive tape and took measurements at each mark left by the spark generator. With the distance and the time we created 2 graphs using Microsoft excel.

In the conclusion to this lab I believe our results were pretty good. A few things to take into consideration that could have brought our value of 9.58m/s^2 closer to 9.81 would be taking air resistance into consideration. Another situation that can effect our results is using the meter stick and the accuracy of measurements are not exactly precise. Overall this was an outstanding lab with some good results to some not so good results. One problem that I have with the results was the overall of

class results varied a lot.

Our relative difference

(9.58cm/s^2-9.8cm/s^2)/(9.8m/s^2)*100% = - 2.24%

Questions

Show that, for constant acceleration, the velocity in the middle of a time interval is the same as the average velocity for that time interval?

Vfinal=DeltaX-1/2at^2/t^2=134.9m/s

average velocity=Delta X/Delta t= (11.8cm-9.1cm)/(0.10s-.08s)=135cm/s

Describe how you can get the acceleration due to gravity from your velocity/time graph. Compare your results with the accepted value?

Delta v/Delta t = (Vfinal-Vinitial)/(Tfinal - Tinitial)   (46.7cm-21cm)/(0.25s-0.15s)=257cm/s

Describe how you can get the acceleration due to gravity from your position/time graph Compare your results with the accepted value?

When you graph your results and then conduct a linear fit which will give you the tangent line to the slope which is our acceleration due to gravity.

Here is the graph from the class data  which calculated standard deviation of the mean.

One thing noticed in the class data for the value of g was all of them were under the 9.8m/s^2.

All of the class except for one tables results landed in the 68% within the accepted values.

I believe all of the error in this lab is measurments. which are systematic errors if we had a more precise way of measuring I think the results would be extremely different.

The purpose of the second part of this lab was to calculate the class values and how far from the actual value of g which is 9.81m/s^2.