uncertainties with marbles

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Marble Experiment

In this experiment, I will be measuring the diameter of six medium sized marbles, with strings and micrometer to find out the differences in measurements I get with measuring with strings and micrometer. In addition, I will also be investigating if all medium sized of marbles have different measurements.

I predict that, by using string and measuring the string by a ruler in centimeters, the measurement I make won’t be as accurate as by using a micrometer. This is because when you use the string method, therefore it moves around or keeps slipping off the marbles. It would be really hard to get a perfect measurement, and this might have an effect when comparing the sizes of medium marbles. As well as that, measuring with a ruler the accuracy is only 0.1cm (*10-2m) compare to measuring with a micrometer which it keeps the object in place, and its accuracy is 0.01mm (*10-3m). In addition, I think six different marbles will have different diameters which mean they won’t all be the same due to the process of making the marbles.

The outliers from the results I got. 

This is measured in cm by using string, since we can’t measure diameter with string, this is how we find out diameter. Diameter=Circumference/

The reason why we can’t use the string to measure the diameter of a marble is because don’t know where half of a marble is.

 To find the diameter we first measured the circumference by using strings and measured it in ruler and then divided it by  to get the diameter. The reason why it is not divide by half is because to get a circumference from diameter we need to times it by.

The uncertainties:

  • The +0.3 differences compared to the calculated average pulls the average for the size of marbles up, and also for the -0.2 one it pulls the average down.

Diameter using calculator

Measured in cm (*10-2m)

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  • These are the anomalies that I’ve pointed out from the previous table.

The uncertainties:

Changes in uncertainty after they are calculated:

  • There is an anomaly in this data, because for the average for marble 5 and 6 there is a lot different compare to the overage that is calculated out from all six marbles. One has +0.08 compared to the average and another has -0.07.

Diameter using Micrometer method

Measured in mm (*10-3m)

  • The marble 2 that is measured by a micrometer, I think that the measurement is abnormally perfect. I think that it ...

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