Both dimension and units must agree.
Accuracy and Precision
- Accuracy: The extent to which a reported measurement approaches the true value of the quantity measured.
- Problems with accuracy are due to error
- Reading an instrument wrong causes human error.
- Repeat readings to make sure they are consistent.
- Choosing different methods for readings can cause method error.
- Standardizing the method of taking measurements.
- If an instrument isn't calibrated properly, instrument error can occur.
- Measure from an exact place, like 10 cm. instead of 0 cm.
- Precision: The degree of exactness of refinement of a measurement.
- A lack of precision is typically due to limitations of the measuring instrument.
Significant figures help keep track of imprecision.
- Significant Figures: Those digits in a measurement that are known with certainty plus the first digit that is uncertain.
…
