Evaluating, Concluding, Measurements and Uncertainties

What makes something more precise?

• When your data is spread over a smaller range

• When your data is spread over a bigger range

• When your result is really close to the correct answer

• When all your errors where checked

What does repeatable mean?

• If an experiment can be repeated and the same results are gotten

• If someone else can recreate the experiment using different equipment or methods and gets the same results

• It answers the original question

What is an accurate result?

• One that is really close to the true answer

• One that has a small range in the data

What is the smallest uncertainty you can have?

• 8%

• 12.5%

• 4.6%

• 0.08%

Which are ways to reduce random errors in experiments?

• increasing number of repeats

• decreasing number of repeats

• use more appropriate equipment (e.g micrometer instead of ruler)

• using a computer

• changing the data you are collecting (e.g change experiment)

What is a systematic error?

• errors which are the same every time you repeat an experiment

• errors which make the results a bit different every time you repeat an experiment

• errors which are caused by human error

If you are adding or subtracting data, what should we do to uncertainties?

• Add absolute uncertainties

• Add percentage uncertainties

• Multiply percentage uncertainties

• Multiply absolute uncertainties

If you are multiplying or dividing data, what should we do to uncertainties?

• Add absolute uncertainties

• Add percentage uncertainties

• Multiply percentage uncertainties

• Multiply absolute uncertainties

How do you use error bars to find uncertainty?

• Calculate gradient of best line and worst line - find the difference - this is uncertainty

• Measure the distance between the error bars at either end of your range

• Calculate the gradient of the best line and worse line - find the y intercept - that's your uncertainty

• Calculate the gradient of the best line - use the error bars size and divide by gradient