1.1: Interpreting Errors
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Systematic Error
- Measurements deviate from the correct value by the same amount each time
- Errors have a pattern
Example: Time on a watch is always 5 minutes ahead of the true time
Random Error
-
Errors have no pattern
Example: Everyone’s watch shows a different time
Uncertainty in Measurement
- Number ± error
- It is the amount a number may be off from the correct value
Example: Age ±365 days
Ratio Comparison
- Shows how two numbers compare
- Reduced fraction shows comparison
Example:
\dfrac{65 \text{mph}}{30 \text{mph}} = \dfrac{2.2}{1} \text { (Means one speed is 2.2 times faster than the other)}\nonumber
Percent Error
- Percentage measurements are off from standard/correct value
- Absolute value
\text {Percent Error} = \dfrac{\text {Experimental/Measured Value} - \text {Accepted/Theoretical Value}}{\text {Accepted/Theoretical Value}} \times 100 \% \nonumber