Popcornlab.pdf

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Heading: March 28, 2006 Komal Majahid Partner: Nicole Alimario In this experiment we measured the rate of popping, the number of unpopped kernels, time of first and last pop, and number of simultaneous pops.

Abstract: We observed the first and last pop, simultaneous pops over the time interval, the rate of popping, and the number of unpopped kernels. The objective was to determine the time of all of the things mentioned and relate it to cosmic rays. Using the Audacity program to measure the sound of the poppings by the microphone attached to the door helped record the data. The predictions for this lab are that there will be a few unpopped kernels left in the bag, and a huge amount of the poppings will come a little after half the time has passed of the time interval (1 minute and 40 seconds.)

Theory: The essential idea is that this popcorn experiment is adjacent to determining the speed of cosmic rays. In both cases we determine the number of simultaneous pops over a certain interval and for cosmic rays, we measure the number of coincidences and divide that by time. In both experiments the idea is to determine the rate.

Experimental: Materials used in this lab were a microwave, microphone, popcorn, and the computer software- Audacity program, to record the measurements. First, we put the popcorn in the microwave and put the microphone on the door of the microwave to measure the pops. We started the microwave and waited for the computer to record all the pops until about 1 minute and 40 seconds. After we stopped the microwave, we looked for the first wave, which is the first pop, and the last wave is the last pop. For the simultaneous pops the waves are at higher amplitude at the same time, which would not be as accurate because everyone is going to count the simultaneous pops differently. To make sure the results are the same, we put another bag of popcorn in the microwave to have another data set to be used by the other group.

Data Analysis:

First pop- 38.0436 sec

Second 41.0910 sec Third- 42.1287 sec Fourth- 42.3362 sec Fifth- 42.5984 sec

Multiple pops at 47.665, 50.6156, 53.2698, 53.3681, 53,5319, 58.9605 seconds. The highest number of simultaneous pops was 3 pops at a time, while the rest were mostly 2 pops at a time.

click on this link to view the data chart.pdf

The average of the poppings was  : (0+1+66+81+35) pops/ 100 seconds) = 1.83 pops/sec With about 10 kernels remaining unpopped, the error in these results would be (193-183)/183 * 100= 5.464% standard deviation- 47.937 The rate was different for each interval of 20 seconds- From 0-20, it was 0 pops 21-40, it was (1/20)= 0.05 pops/sec 41-60, it was (66/20)= 3.3 pops/sec 1:01-1:20, it was (81/20)= 4.05 pops/sec 1:21- 1:40, it was (35/20)= 1.75 pops/sec These results do agree with theoretical predictions where a large amount of the kernels pop at the end of the time interval when all the kernels have been heated for quite some time.

Conclusion: The simultaneous pops were going to be in the middle of the time interval because it takes time to heat up the water in the kernel. There was also a huge gap between the last pop and the time the door was opened because no more kernels were going to pop, which are exactly as predicted due to the fact that we would never get 100% accurate results. Error sourced could be that the waves could also be people talking in the class or they could be caused the noise of the fan in the class. In addition, for the simultaneous pops it is difficult to determine how many pops there are actually occurring-which is also an error source because everyone would count them differently.

Remarks: To improve the experiment we could do more trial and average the results. Also to make sure that there is no extra noise in the room besides the popping popcorn because otherwise the waves on the graph could be taken as popping when they are actually not.