Physical Science 8th grade (1).pdf

Error in your experiments with motion you will use a

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Error In your experiments with motion you will use a photogate timer to make measurements to the nearest 0.0001 seconds. You will notice that you rarely get the exact same time three times in a row even if you do the exact same thing . This is because any measurement always contains some error . Error is the difference between a measurement and the true value of what you are trying to measure. The errors are small if the experiment is accurate. The average When you make many measurements of the same thing you will notice that they cluster around an average value. Some measurements are more than the average and some are less. To calculate the average you add up all the measurements and divide by the number of measurements you have. For example, the average of the times in Figure 2.18 is 0.1253 seconds. Why taking the average is useful The average of several measurements is usually more accurate than a single measurement. The average is more accurate because errors in the negative direction partially cancel errors in the positive direction.
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