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What's the answer 2 these sciency questions to do with experiments?

Heya, I have a couple of sciency based questions I wondered if anyone could answer!

  1. why is there variation in results when doing an experiment so for example we timed something and the first time it took 8 seconds, the second 9 seconds and the third 7 seconds. Wot could be the reasons for this variation?

And 2) our stopwatches time to the nearest 0.01 seconds but we were told to record our results to the nearest second, why? (and we have been told there was a reason!)

Any answers greatly appreciated!!!

Thanks x

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Answer #1

  1. Human error, and it is very difficult for humans to exactly, and perfectly conduct an experiment… using a stop watch I’m guessing?

  2. I would say that we round for a couple of reasons:

One is to estimate, as you suggest: if we have more or less exact numbers, but only need an approximate product, say, then we can save work by rounding the numbers before we do our calculations. This implies that our data are more accurate than we need (at least at the moment).

Another is to reduce the accuracy of a result to reflect the accuracy of the data. You can read about this by searching for “significant digits.” For example, if we measure the sides of a rectangle as 3.1 and 5.7 inches, then the area can be calculated as 17.67 square inches. But with only two digits of precision in the lengths, we can only be sure of two digits in the answer, so we should round the answer to 18 square inches to show how precise our numbers are.

In each case we are reducing the precision of our numbers for some reason.

Hope this helped!

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