CONTENT OBJECTIVE
WHAT THE HECK DO I NEED TO BE ABLE TO DO?
I can collect data and make
measurements with accuracy and
precision.
ooooooh….007, you’re so much better
looking than 006!
ooD
7ado
….but your accuracy and precision
aren’t nearly as good as 00Dado!
Accuracy and Precision
Accuracy refers to
A. _______________
the closeness of
measurements to the correct
or accepted value of the
quantity measured.
Accuracy and Precision
Precision refers to the
B. _____________
closeness of a set of
measurements of the same
quantity made in the same
way.
High
Precision
High
Accuracy
High
Precision
Low
Accuracy
Low
Precision
Low
Accuracy
Low
Precision
High
Accuracy
(On Average)
Accuracy and Precision
percent _________
error is
C. ___________
calculated by subtracting
the experimental value from
the accepted value, dividing
the difference by the
accepted value, and then
multiplying by 100.
Percent Error
(Valueaccepted — Valueexperimental)
Valueaccepted
x 100
Percent Error
1. Percent error has a
positive
___________ value if the
accepted value is greater
than the experimental value.
Percent Error
Calculate percent error in an
experimental mass measurement of 5g
if the accepted value is 10g.
Known:
p.
Unknown:
Experimental Mass
5g
Accepted Mass
10g
Percent Error
?
Percent Error
H.
Valueaccepted— Valueexperimental
x 100
Valueaccepted
a.
10g
—
5g
10g
.5g x 100 = 50%
T.
Should
Is
my answer
my answer
reasonable?
be positive?
x 100
Percent Error
2. Percent error has a
____________
negative value if the
accepted value is less than
the experimental value.
Percent Error
Calculate percent error in an
experimental length measurement of
10cm if the accepted value is 5cm.
p.
Known:
Unknown:
Experimental Length
10cm
Accepted Length
5cm
Percent Error
?
Percent Error
H.
Valueaccepted —Valueexperimental
x 100
Valueaccepted
a.
— 10cm
5cm
5cm
-1cm
T.
x 100 = -100%
Is
Should
my answer
my answer
reasonable?
be negative?
x 100