length: distance between two points meter (m) mass: how much matter something has gram (g) volume:...
TRANSCRIPT
•Length: distance between two points
meter (m)
•Mass: how much matter something has
gram (g)
•Volume: how much space something takes up liter (L)
•Temperature: how warm or cold something is
degrees Celsius (°C)
•Prefixes + standard base unit
• Centi + meter = Centimeter
• Kilo + liter = Kiloliter
•The three most common prefixes:
kilo
centi
milli
kilo hecto decaBase Units
m/g/Ldeci centi milli
• Scale moves in multiplications of 10
• Example:Centimeters are 10 times larger than millimeters
1 centimeter (cm) = 10 millimeters (mm)
kilo hecto decaBase Units
m/g/Ldeci centi milli
• Centimeters are 10 times larger than millimeters
• It takes more millimeters for the same length
• For each “step” right, multiply by 10
• Trick: move the decimal point one place to the right for each “step” desired
•Example: change meters to centimeters1.00 meter = 10.0 decimeters = 100. centimeters
kilo hecto decaBase Units
mdeci centi milli
• For each “step” left, divide by 10
• Trick: move the decimal point one place to the left for each “step” desired
•Example: change meters to kilometers
1100 meters = 110.0 decameters = 11.0 hectometers = 1.1 kilometers
kilo hecto decaBase Units
mdeci centi milli
• If you move to the left in the diagram, move the decimal to the left
• If you move to the right in the diagram, move the decimal to the right
kilo hecto decaBase Units
m/g/Ldeci centi milli
Measurement
How do scientists measure…
• … mass?
Scale
How do scientists measure…
• … mass?
• What is the basic unit for mass?
gram (g)
Scale
How do scientists measure…
• … length/height?
Ruler
How do scientists measure…
• … length/height?
• What is the basic unit for length/height?
meter (m)
Ruler
How do scientists measure…
• … temperature?
Thermometer
How do scientists measure…
• … temperature?
• Basic unit for temp?
degrees Celsius (C)
Thermometer
How do scientists measure…
• … the volume of a liquid?
Flask Beaker
Graduated
Cylinder
How do scientists measure…
• … volume of a liquid?– Flask, beaker, graduated cylinder
• What is the basic unit for liquid volume?
liter (L)
Which is best for measuring liquid volume?
Which is best for measuring liquid volume?
Why is it the best?
ACCURACY
What is accuracy?
What does it mean to measure something accurately?
What is the difference between accuracy and precision?
If your measurements are accurate, are they precise?
If you measurements are precise, are they accurate?
Accuracy vs. Precision
• The more ACCURATE a measurement is, the closer it is to the TRUE/CORRECT/EXACT value.
• The more PRECISE a measurement is, the more REPRODUCIBLE/ REPEATABLE it is.
Accuracy vs. Precision
Accuracy vs. Precision
High Accuracy, Low Precision
Low Accuracy, High Precision
Another Way of Looking At It
ACCURATELY reading volume:
Where should you be looking?
ACCURATELY reading volume:
Where should you be looking?
meniscus
How big is BIG? How small is SMALL?Number Sci. Not. Unit Prefix Abbreviation
1,000,000,000,000 1012 tera T1,000,000,000 109 giga G
1,000,000 106 mega M1,000 10? ? ?0.01 10-? ? ?
0.001 10-? ? ?0.000,001 10-6 micro µ
0.000,000,001 10-9 nano n0.000,000,000,001 10-12 pico p
How big is BIG? How small is SMALL?Number Sci. Not. Unit Prefix Abbreviation
1,000,000,000,000 1012 tera T1,000,000,000 109 giga G
1,000,000 106 mega M1,000 103 kilo k0.01 10-2 centi c
0.001 10-3 milli m0.000,001 10-6 micro µ
0.000,000,001 10-9 nano n0.000,000,000,001 10-12 pico p
Unit Conversions
• You know your height in feet/inches. How can you convert this to meters/centimeters?
DIMENSIONAL ANALYSIS