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your prediction, then estimate which are the most important. Conclusion
Consider your conclusion the wrapping paper and bow tie of your report. At this point, you
should already have said most of the important things, but this is where you collect them in
one place. Remind your audience what you did, what your result was, and how it compares
to your prediction. Tell her what it means. Leave her with a sense of closure.
Quote your result from the Analysis section and interpret it in the context of the hypothetical
scenario from the Introduction. If you determined that there were any major shortcomings in
your experiment, you might also propose future work to overcome them.
If the Introduction was your attempt to justify your past funding, then the Conclusion is your
attempt to justify your future funding. What Now?
Read the sample reports included in this manual. There are two; one is an example of these
instructions implemented well, and the other is an example of these instructions
implemented poorly. Then, talk to your TA. He can answer any remaining questions that you
might have.
There is a lot of information here, so using it and actually writing your lab report might seem
a little overwhelming. A good technique for getting started is this: complete your analysis
and answer your question before you ever sit down to write your report. At that point, the
hard part of the writing should be done: you already know what the question was, what yo=0 and that the Vy graph would be a linear line with Vy(z)=10z.
Next, we fit the functions to the data points for the velocity graphs. We got the predictions exactly right.
We then printed our data for the street hockey ball and closed MotionLab.
We repeated this process for a baseball with a mass of 143.0g. It was mostly the same, with some exceptions. The
y(z) fit was y(z)=4.85zˆ2 instead of y(z)=5zˆ2. The Vy(z) prediction was Vy(z)=9.7z instead of Vy(z)=10z. These
were also exactly right, so the Vy(z) fit was the same.
At the end of the lab, everybody put their data on the board so we would have enough to do the analysis. We copied
it down. Then we were finished, so we started the next experiment. Data Ball 1
mass: 12.9+/0.05g
x prediction: x=0z
x fit: x=0z
y prediction: y=4.9zˆ2
y fit: y=4.8zˆ2
Vx prediction: Vx=0z
Vx fit: Vx=0z
Vy prediction: Vy=9.6z
Vy fit: Vy=9.6z
Ball 2
mass: 48.8+/0.05g
x prediction: x=0z
x fit: x=0z
y prediction: y=4.9zˆ2
y fit: y=5.1zˆ2
Vx prediction: Vx=0z
Vx fit: Vx=0z
Vy prediction: Vy=10.2z
Vy fit: Vy=10.2z
Ball 3
mass: 55.8+/0.05g
x prediction: x=0z
x fit: x=0z
y prediction: y=4.9zˆ2
y fit: y=4.9zˆ2
Vx prediction: Vx=0z
Vx fit: Vx=0z
Vy prediction: Vy=9.8z
Vy fit: Vy=9.8z Ball 4
mass: 56.7+/0.05g
x prediction: x=0z
x fit: x=0z
y prediction: y=4.9zˆ2
y fit: y=4.95zˆ2
Vx prediction: Vx=0z
Vx fit: Vx=0z
Vy prediction: Vy=9.9z
Vy fit: Vy=9.9z
Ball 5
mass: 57.7+/0.05g
x prediction: x=0z
x fit: x=0z
y prediction: y=4.9zˆ2
y fit: y=5.0zˆ2
Vx prediction: Vx=0z
Vx fit: Vx=0z
Vy prediction: Vy=10.0z
Vy fit: Vy=10.0z
Ball 6
mass: 143.0+/0.05g
x prediction: x=0z
x fit: x=0z
y prediction: y=4.9zˆ2
y fit: y=4.85zˆ2
Vx prediction: Vx=0z
Vx fit: Vx=0z
Vy prediction: Vy=9.7z
Vy fit: Vy=9.7z 269 APPENDIX: SAMPLE LAB REPORT Ball 7
mass: 147.6+/0.05g
x prediction: x=0z
x fit: x=0z
y prediction: y=4.9zˆ2
y fit: y=4.8zˆ2
Vx prediction: Vx=0z
Vx fit: Vx=0z
Vy prediction: Vy=9.6z
Vy fit: Vy=9.7z Analysis
We can calculate the acceleration from the MotionLab fit functions. To do this, we use the formula x =
x0+v0t+1/2atˆ2. Then a is just 2 times the coefficient of zˆ2 in the position fits. This gives us
Ball 1: a=9.6
Ball 2: a=10.2
Ball 3: a=9.8
Ball 4: a=9.9
Ball 5: a=10.0
Ball 6: a=9.7
Ball 7: a=9.6
The acceleration can also be calculated using the formula v=v0+at. Then
a is just the coefficient of z in the velocity fits. This gives us
Ball 1: a=9.6
Ball 2: a=10.2
Ball 3: a=9.8
Ball 4: a=9.9
Ball 5: a=10.0
Ball 6: a=9.7
Ball 7: a=9.7
We know that the acceleration due to gravity is 9.8m/sˆ2, so we need to compare the measured values of the
acceleration to this number. Looking at the data from the fits, we can see that they are all close to 9.8m/sˆ2, so the
error in this lab must not be significant. Ball 3 actually had 0 error.
We need to analyze the sources of error in the lab to interpret our result. One is human error, which can never be
totally eliminated. Another error is the error in MotionLab. This is obvious because the data points don’t lie right on
the fit, but are spread out around it. Another error is that the mass balance could only weigh the masses to +/0.05g,
as shown in the data section. There was error in the fisheye effect of the camera lens. There was air resistance, but
we set that to 0, so it is not important. Conclusion
We predicted that a would be 9.8m/sˆ2, and we measured seven values of a very close to this. None was off by
more than 0.4m/sˆ2, and one was exactly right. The errors are therefore not significant to our result. We can say that
the canisters fall at 9.8m/sˆ2. This experiment was definitely a success. 270...
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This document was uploaded on 02/23/2014 for the course MANAGMENT 2201 at University of Michigan.
 Spring '14

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