Physics Error And Uncertainty

Front 1

Type: Absolute

Back 1

the actual numerical uncertainty
ex. 13.21 m +/- 0.01 m

Front 2

Type: Fractional

Back 2

divide the uncertainty by the value
ex. 0.1/2.0= .05

Front 3

Type: Percentage

Back 3

multiply fractional uncertainty by 100
ex. 0.1/2.0 x100 =5%
*always round to one significant figure

Front 4

Propagation of Error:
Adding or subtracting

Back 4

add absolute uncertainties

Front 5

Propagation of Error:
Multiplication, Division,

Back 5

add percentage uncertainties

Front 6

Propagation of error:
Powers

Back 6

when calculation involves raising to a power, multiply the percentage uncertainty by the power

Front 7

Rules for unknown uncertainty:
analogue equipment . . .

Back 7

is +/- half of the smallest scale division

Front 8

Rules for unknown uncertainty:
digital equipment . . .

Back 8

is +/- 1 of the last known digit
*if the uncertainty of the device is known, use this value instead

Front 9

Rules for unknown uncertainty:
stopwatch controlled by a person . . .

Back 9

should be recorded to the +/- 0.1 of a second

Front 10

Rules for unknown uncertainty:
If it is unknown . . .

Back 10

+/- 1 of the smallest significant figure

Front 11

to find uncertainty for a mean . . .

Back 11

use largest discrepancy between the mean and the maximum or minimum value.

Front 12

to find uncertainty of a data value divided by number of trials. . .
ex. swing back and forth 10 times in 36.27s +/- 0.01s

Back 12

dividing by amount of trials also divides uncertainty

ex. one swing takes 3.627s +/- 0.001s