Definitions Flashcards
What is an uncertainty?
Interval which the true value can be considered to lie
How can you reduce percentage uncertainty?
Make resolution/scale divisions smaller
Make the value larger
How does repeated measurements decrease uncertainty?
- Timing a large number of oscillations minimised the percentage uncertainty in the measurement
- Minimises effect of random errors
- Taking a repeat measurement allowed a check for gross timing errors.
What is error?
An error is the difference between a measurement/result to true value
What are 2 types of errors?
Systematic error
- Use of faulty instruments/ flaws in experimental method
Random error
- Errors made by person carrying out measurement e.g timing inaccuracy
How can you tell which type of error has occured?
Systematic error
- Expected line through origin does not pass through origin
Random Error
- Large scatter of points around line of best fit
What is accuracy?
Accuracy is how close measurement is to true value
How can you increase accuracy in practical?
Timing over multiple oscillations
Micrometer for small distances
use of fiducial marker
set square
plumb line
What is precision?
How close measurements are to one another.
Why is data logger used?
- Record continuously and can do short intervals of time
- Removes human error to reduce uncertainty
Whats the purpose of calculating mean?
Reduce effect of random errors
How to calculate uncertainty?
Range of values ÷ 2
Resolution/2
