The purpose of this lab was to find evidence that in the absence of external forces, the acceleration of gravity is 9.8m/s . The professor had a tall device set up from which an object fell freely to the floor and was stuck by electricity 60 times per second as it fell. This left a black spot on the paper which we then used to collect our data. With this experiment we wish to understand why acceleration due to gravity is of 9.8m/s.
Data Collection:
1.We taped down our strip of paper and and began measuring the distance of each individual dot to the origin.
2. We recorded the data:
3. Our recorded values are our x. And out t is simply (1/60) because the electric impulses were fired at 60hz.
4. Using Excel, we calculated the change in x as x minus our previous x.
5. Our v (velocity) was our change in x divided by out time.
6. We graphed our velocity and time graph and noticed a straight line.
7. Next we graphed out velocity graph to see what it would look like. we used the time column and velocity columns.
8. Right after that, we graphed a position time graph, here labeled Time.
9. Finally, we compared our g values with our classroom. The g value is the slope of the velocity graph. Because we left it in centimeters we divided it by 1000.
10. We recorded all of our class values:
11. These results were then averaged.
12. The deviation from mean was obtained by subtracting the value of g from the average g.
13. The deviation from mean was obtained by squaring the deviation from mean.
14. The means where then added all together and averaged.
15. Next we took the square root of the average to obtain our average deviation value. In our case it was found to be 20.12 .
Analysis:
During this experiment it became evident that the results were not precise as we all had different g values and our deviation average was considerably high. Therefore it was concluded that this is not a good experiment for the measurement of gravity. Our class found that the average force of gravity as defined by this experiment is 9.5m/(s*s). Although this is somewhat close to the accepted 9.8m/(s*s) it is still far from that value. I think that the reason why our measurements were not as close to g as they could have been may involve some air friction, lack of precise measuring instruments, and human error in measurement. Overall we learned that gravity is a constant force that affects all masses equally. We also learned that measuring this forces is not easy but it is doable. It is now evident that we must always factor in the fact that no measurement is ever precise as there are always factors that make our values stray from the true ones. There is always a chance for error. However, we also learned that we can compensate for this error my measuring our deviations.
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