1What are four rules of Significant Figures?
1) Non zero digits are always significant
2) all final zeroes after the decimal point are significant
3) zeros between two significant digits re significant
4) zeros for spacing a decimal point are not significant
2How many significant figures in 500?
one
3How many siginificant figures in 0.00054
two
4How many siginificant figures in 100250200?
seven
13What is accuracy
How close a number is to an accepted value
14what is precision
How close a measurement is to similar measurements
15Random error is...
an error due to inexperience of the observer and the diffuculty of reading instruments.
16how can random error be reduced
repeat measurements
17random error affects
precision
18systematic error is...
a error due to incorrectly calibrated intruments
19how is systematic error reduced
it can't be reduced
20systematic error affects...
accuracy
21Uncertainty is...
a value that characterizes the spread of the values that could reasonably be attributed to the process of measurement or the properties of the object being measured
22Which error is uncertainty
random error
23How do you manage error?
1) be careful
2) choosing and calibrating appropriate measuring devices
3) be consistent in methods of measuring
4) use graphs to identify and represent error
24What are the two kinds of uncertainty
Absolute and Relative
25What is Absolute uncertainty
actual uncertainty in the numbers you are working with
26how many significant figures (at most) in absolute uncertainty
2
27what is relative uncertainty
the percent or fractional uncertainty in your numbers
28Sum of addition and subtracting uncertainties is...
absolute uncertainties
29Sum of multiply and divide uncertainties is...
relative uncertainties
30Sum of power relationships (sqaure, sqaure root, etc) uncertainties is...
relative uncertainties
31if y=a +- b
change in y = change in a + change in b
32if y=ab/c
then (change of y/y) = (change of a/a) + (change of b) + (change of c/c)
33Uncertainty formula
(max-min)/2
34if y=a^n
(change of y/y) = |n(change of a/a) |
36word for gradient
slope
37what are three specific values that we can determine from a graph
1) slope of line
2) y-intercept + x intercept
3) area
38what are min-max slope lines used for
to find a value with uncertainty in slope and/or y intercept
39steps 1-3 to making min-max lines
1) plot data points with uncertainty and find line of best fit as y=mx+b
2) draw a line with greatest slop is is possible (passing through all error bars)
3) draw a line with smallest slop is is possible (passing through all error bars)
40steps 4-5 to making max-min lines
4) find the slope and y-intercept of max and min slope lines
5) your final uncertainty in the slope of your best fit line is: (max slope-min slope)/2 (same with y-intercept)
41What is equation of linear uncertainty?
y= (avg m+- unc)x + avg b+- unc