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inginair

Physics HL Help

So tomorrow I have a Physics quiz, and there are still some things that confuse me. The quiz is about uncertainties. I know how to determine the uncertainty, but there are still 2 things that I cant understand.

A) Why does an accurate experiment have less systematic errors, and a precise experiment have less random errors?

B) Graphs of accuracy & precision. Why does a systematic error have readings that are on the "best" line, while the random error graph has points that are not on the best fit line?

Thanks

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I can't help with number two, but for number one, I was always emphasized the difference between precision and accuracy as precision could be like throwing darts on a board in the same small region so that you produce the same results that may or may not be accurate. Accuracy has to do with correctness. With the dart example, an accurate throw would land in the middle of the dart board.

So when you say you have a precise experiment, you're saying you're getting the same results, and your probability of random error lowers because random errors might occur in one instance. If you're performing an experiment and the wind blows one time, then if you have a precise experiment where you're focusing on doing many trials, then the probability will lower. think of it like this: The probability of a random error occurring once is 1/8. The probability of it occurring a second time is (1/8)2, right? So the probability goes way down.

As for systematic errors decreasing in accurate experiments, when you're focusing on every little detail, then you're going to be careful that you don't misuse the equipment or incorrectly manipulate the data, etc. The fact that it's accurate means you've eliminated careless errors on your part. Does that make any sense?

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