Phy 201
Your 'cq_1_01.2' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** **
The problem:
Answer the following:
• How accurately do you think you can measure the time between two events using the TIMER program?
answer/question/discussion: I think that you can measure two events with the timer program reasonably accurately. As with all measuring devices, there is some error. I recall reading that the timer program is accurate to within .01 seconds. This means that when taking a measurement, it is not reliable to record data beyond the hundredths place. Also, accuracy can also be disturbed by the person running the experiment. In order to get a more accurate result, one would have to push the start timer button and the stop timer button at exactly the right moments. Variations in this could also ruin the accuracy of the experiment.
• What is the shortest time interval you think you would be able to measure with reasonable accuracy?
answer/question/discussion: If the timer were automated I would answer .01 seconds because the timer is accurate to this measure. However due to human error in the timer device I will have to say .1 seconds. It seems unlikely that a human clicking the button could accurately measure .01 seconds, however .1 seconds could be done with very speedy fingers.
• How does the percent error in timing intervals change as the time between the events gets smaller?
answer/question/discussion: The percent error will increase as timing intervals get smaller. The timer will get less accurate meaning the percent error will increase. Seeing as the timer is only accurate to the .01, moving to lower values then this will definitely present error. Percent error could also be larger for larger values because there is a greater chance for larger errors. Recording a 60 second lap in a race may have error of up to second while recording the time it takes a ball to fall one inch may be off by .1 second. By ratio, it seem that the smaller values would have more error but I am not sure.
The ratio is the key. For short time intervals the denominator, which is the time interval, is smaller. So a given error will have more effect on a short time interval.
• How accurately are you able to measure the positions of the ball and the pendulum in the initial video?
answer/question/discussion: I felt that I could measure the positions of the ball and the pendulum fairly accurately. The screen was slightly blurred, but there was not any other obstruction to measurement. I felt that my measurements were easily accurate to the inch and may have been accurate to the .5 inch. I would not go as far as saying they were accurate to the 0.1 of an inch or the cm seeing as the screen was blurred. It would be interesting to know what the true error in my recordings is.
** **
20 mins
** **
&#This looks good. Let me know if you have any questions. &#