1. Metric

2. Our country still uses an old system with non uniform measurements such as:
fractions of an inch inches to a foot…. 3 feet to a yard…. 5.5 yards to a rod rods to a mile... 43,560 sq ft to an acre...
But almost all other countries use the metric system, which is disadvantageous for us.

3. But we do use the metric for a few things:
We buy cola in liters... We buy memory cards in bites… We run 10 km races... We swim in 25 meter pools...
Why haven’t we switched entirely to metric?

4. Measuring Length in meters
When measuring a person we would use meters.
If we are measuring an ant, would meters still be feasible? What should we use?
If we are measuring the distance from your house to the school, what should we use?
Always pick a prefix with a value close to what you are measuring.

5. The Metric System Units of Measurement: Mass grams g Length meters m
Time seconds s
Temperature Kelvins K (or Celsius)
Volume liters 1ml = 1cm3
Heat joules J

6. Name the units: Mass Volume Length Temperature Energy Time Grams
Liters
Meters
Kelvin (Celcius)
Joules
Seconds

7. The Metric System Prefixes: Deci d 10-1 Centi c 10-2 Giga G 109
Milli m 10-3
Mega M 106
Micro u 10-6
Kilo k 103
Nano n 10-9
Pico p 10-12

8. The Metric System
If a unit is getting larger (m  km) the number must get smaller. If the unit gets smaller (m  cm) the number gets larger.
Examples:
cm = km
mL = L
g = ug
3.567
98400

10. Temperature Conversions
Notice that each scales is marked with BP and FP of water as well as absolute zero.
The degree size of Celsius is equal to Kelvin. Therefore we adjust only for zero points: C = K – 273
K = C + 273

11. Thinking in Celsius -10° Celsius = frigid (14° F)
0° Celsius = cold (32° F)
10° Celsius = cool (50° F)
20° Celsius = comfortably warm (68° F)
30° Celsius = hot (86° F)
40° Celsius = very hot (104° F)
50° Celsius = Phoenix Hot (120°F)

13. Density

14. Density depends on:
Mass: the amount of matter an object contains. (This is different than weight, which is mass plus gravity)

15. Density also depends on…
Volume: amount of SPACE an object takes up

16. How can we measure volume?
l x w x h (regular solid)
ex. V = 1cm3
Graduated cylinder (liquids)
Read bottom of MENISCUS
ex. V = 27.5 mL

17. Measuring Volume: Irregular Solid
Water displacement method:
Measure initial volume
Measure final volume with object
The Difference is the volume of the object

18. Example
What is the volume of the solid
46 mL
54 mL
8 mL
26 mL

19. Density Ratio of mass of an object to its volume Use density formula
Located on Table T

20. Example 1
What is the density of an object with a mass of 60 g and a volume of 2 cm3?
60/2 = 30 g/cm3

21. Example 2
An object has a volume of 800 cm3 and a density of 13 g/cm3. Find its mass.
13 = x
800
10400g

22. Example 3: How to solve for mass or volume if density is not given:
USE TABLE S
Example:
The volume of an aluminum sample is 100 cm3. What is the mass of the sample?
The density of aluminum on table S is 2.70g/cm3
2.70 = x
100
270 g

23. Example 4
Determine the volume of an aluminum object with a mass of 54g.
2.70= 54 x
2.70 x = 54
20 cm3

24. Is density constant?
Draw representations of liquid water when it is cold and when it is hot.
In which condition will the particles be closer together?
In which condition will the density be greatest?
Let’s describe how a Galileo thermometer works.