Free Fall Lab

Free Fall Lab--determination of g

Purpose: 
To examine the validity of the statement: In the absence of all other external forces expect gravit, a falling body will accelerate at 9.8 m/s^2.

Experiment:
1.set up the apparatus as shown below
2.Turn the dial hooked up to the electromagnet up a bit
3.Hang the wooden cylinder with the metal ring around it on the electromagnet
4.Turn on the power on the sparker thing
5.Hold down the spark button on the sparker box.
6.Turn the electromagnet off so that the thing falls
7.Turn off power to the sparker thing
8.Tear off the paper strip and line up a meter stick to record the position of each dot

Data collection and analysis:

1.In Excel, put in the column of time, distance, delta x, Mid-interval time, and Mid-interval speed.

2.Enter the data collected in the experiment.

3.In cell C2 enter =(B3-B2) to get delta x and drag down the column

4.In cell D2 enter =A2+1/120 to get Mid-interval time and drag down the column

5.In cell E2 enter =C2/(1/60) to get Mid-interval speed and drag down the column

Graphing

1.Select columns D and E. Choose an XY (Scatter) graph with the points not connected.

2.Add Trend line, choose linear. Choose "Display equation on chart" and display R-Squared value on chart.

3.Select columns A and B. Follow the same steps above expect choosing polynomial fit of order 2.

Analysis of Errors and Uncertainty:

1..In Excel, put in the column of g, deviation, abs deviation, and deviation^2.

2.Collect and enter the value of g from nine different groups in column B

3.In cell B11 enter =average(B2:B10) to get the average value of g

4.In cell C2 enter =B2-$B$11 to get deviation and drag down the column.
5.In cell D2 enter =ABS(C2) to get abs deviation and drag down the column.

6.In cell E2 enter =C2^2 to get deviation^2  and drag down the column.

Summary: 

Through this lab we can examine the value of gravitational acceleration without any other external forces expect gravity, and we learn how to use Excel to help us organize the data and calculate the functions in a short time. Also, we learn how to test the errors and uncertainty of the data based on the deviation.