1. Measurement
A person can only measure 7 basic entities. The following are the basic entities
Mass
Time
Amount of matter
Luminosity
Electric current
Distance
Temperature
Everything else is a derived unit.

2. Basic Metric Units Entity Base Unit Name Abbreviation Mass kilogram kg
Length
meter m
Time
second s
Amount of matter
mole
mol
Electric current
Amphere A
Luminosity
Candella Cd
Temperature
Kelvin K

3. Metric Prefixes Name Abbreviation Meaning Size Relative to Base Mega M
All are bigger than the base.
Kilo k
1000
Hecto h
100
Deca da 10
Base
Any one of the base unit
Deci d
1/10
All are smaller than the base.
Centi c
1/100
Milli m
1/1000
Micro μ 1/

4. Derived Units Derived Unit Units Density kg/m3 Force kgm/s2 Momentum
Work Nm
Power
Nm/s
Acceleration
m/s2
Volume m3
and hundreds of others

5. Timberlake LecturePLUS
Accuracy
How close a measurement is to the actual or true value
good accuracy
true value
Poor Accuracy
Timberlake LecturePLUS 5

6. Timberlake LecturePLUS
Precision
How well several measurements agree with each other
good precision
poor precision
Timberlake LecturePLUS 6

7. How to make measurements
We want to make accurate and precise measurements in science
In order to do so, there is a 3 step process
Study (look at the scale on the tool) the measurement tool you are about to use and determine the value of the smallest marked interval.
2. For metric tools you declare the precision to one tenth of the value of the smallest marked interval.
3. Now finally look at the tool and make your measurement and make the measurement match your precision.
Lets practice

8. Lets make some measurements!!!1
0.5
0.75
0.25
Smallest marked
Interval ______
Precision _____
Measurement _____
Smallest marked
Interval ______
Precision _____
Measurement _____
Smallest marked
Interval ______
Precision _____
Measurement _____

9. 0.2
0.3
0.4 10 20 30
500
600
700
0.2
0.4
0.6

10. 0.2
0.3
0.4
300
400
500 8 9 10
0.05
0.06
0.07