Module 1 Development of practical skills in physics Flashcards
What is the independent variable?
The thing you change
What is the dependent variable?
The thing you measure
What is a control variable?
A variable you keep the same in an experiment. E.g. all the variables but the Independent and dependent
What is an instrument’s sensitivity?
A measure of how much the quantity it’s measuring needs to change by for the change to be detected
Sensitivity = change in output / change in input
What is the response time of an instrument?
How long it takes for the output to change after a change in input
Why do you repeat measurements at least three times?
Repeated measurements can reduce the effects of random errors in your results and make spotting anomalous results easier
Which axes to the independent and dependent variables go on?
Independent: x axis
Dependent: y axis
What is a precise result?
Precision = reliability
The smaller the range that the repeats for each measurement are spread over, the more precise your data
A precise result is one that is repeatable and reproducible
Explain what repeatable means. Explain the link to precision
You can repeat an experiment multiple times and get the same results. For experiments, doing more repeats enables you to assess how precise your date is – the more repeats you do, and the more similar the results of each repeat of, the more precise your data
Explain what reproducible means
If someone else can recreate your experiment using different equipment or methods, and get the same results you to, the results are reproducible
What is a valid result?
A result that answers the original question, using precise data. If you haven’t controlled all the variables, your results won’t be valid, because you won’t just be testing the effect of the independent variable.
What is an accurate result?
A result that’s really close to the true answer.
What is absolute uncertainty?
The total uncertainty for a measurement
What is the percentage uncertainty?
The uncertainty given as a percentage of the measurement
What are the issues with random errors in your results? How do you reduce this problem?
The less random error there is in the measurement, the more precise results. Increasing the number of repeats could help to reduce the effects of random errors in your results
You can reduce the random error in your experiment by using the most appropriate equipment e.g. a ruler with a higher resolution
