Measurement Measurement Definitions 1 Parallax apparent shift in

Measurement

Measurement Definitions 1. Parallax –apparent shift in a measurement when viewed from different angles

Measurement Definitions 2. n Accuracy – how far from the actual value a particular measurement falls finding % error

Measurement Definitions 3. Precision – how close repeated measurements are to one another n A measurement can only be as precise as the measuring instrument allows

Significant Digits n n all the digits of a measurement that are certain; plus a digit that estimates between 2 divisions on the measuring instrument

Example 1: Meter Stick 8 9

Rules for Digits 1. 2. All non-zero digits are significant. All zeros are significant EXCEPT: n Leading zeros n Ending zeros when there is no visible decimal point in the

Examples: 1. 2. 3. 4. 5. 125. 605 300. 0. 250 0. 000605 6. 7. 8. 9. 508 0. 00504 700 610. 0 3. 15 x 109

Rounding Rule for Adding or Subtracting n Round your answer so that it has the same number of decimal places as the measurement with the least number of decimal places.

Ex. 1: 16. 2 m + 5. 008 m + 13. 48 m = 34. 688 m Round to 34. 7 m

Rounding Rule for Multiplying or Dividing n Round your answer so that it has the same number of significant digits as the measurement with the least number of significant digits.

Ex. 2: 13. 507 m x 3. 60 m = 48. 6252 2 m Round to 48. 6 m 2

Ex. 3: 153 s x 3. 8 s = 581. 4 2 s Round to 580 s 2