Metrics
What is the acronym for the metric system and what does it stand for?
K H D M D C M
K H D (U) D C M
***King Henry Died Monday Drinking Chocolate Milk
Kilo Hecto Deka Meters or Units deci centi milli
Convert 56.010 in to cm
2.54 cm = 1 inch
Make answer as precise as possible.
56.010 in x 2.54 cm/1 in = 142.2654 cm
Round 0.00023350 to 3 significant figures.
What is 0.000234?
What two things are NOT considered in SIG FIG rules?
definitions of prefixes for metric conversions
integers used in fractions
Exact numbers
The density of a known object is 7.14 g/mL.
After taking the mass and volume, then dividing it, student A measured 7.998 g/mL. Student B measured 7.19 g/mL.
Which student is more precise? More accurate? WHY?
Student A is more precise (detailed in measurement)
Student B is more accurate (closest to known measurement)
What do these prefixes mean?
centi
milli
kilo
centi = 1/100th (.01)
milli = 1/1000th (.001)
kilo = 1000
A nurse injects 45 cc's of medicine into a patient. How many L is that?
cc's = cm^3 = 1 ml
45 ml x 1L/1000ml = .045 L
OR
45 ml x .001L/1ml
3100.0 x 10^2
5
Formulas for converting between C and F
F = 9/5 (C) +32
C = 5/9(F - 32)
convert to scientific notation
0.000897
8.97 x 10^-4
Metric unit for:
mass
distance
volume
time
mass = gram (g)
distance = meter (m)
volume = liter(L)
time = second (s)
Convert 78.2 C into F.
Use sig figs
F = 9/5 C +32
F = 9/5(78.3) +32
140.94 = 141 +32 = 173
***Exact numbers (32) and Integers don't count for sig figs (9/5 doesn't count)
How many sig figs does 376, 000. have?
6 because of the decimal
Formulas for converting between K and C
K = C + 273.15
C = K - 273.15
convert to standard notation
6.3460 x 10^6
6346000
Use the factor label-method (dimensional analysis)
use sig fig rules
Convert 14, 379 g to kg
Show work
14,379 g x 1kg/1000g = 14.379 kg
Convert 344.1 K to F
show work
use sig fig rules for mult/division, add/subtract
K = C + 273.15
C = K - 273.15
F = 9/5 (C) +32
C = 5/9 (F -32)
C = 344.1-273.15 = 70.95 = 71.0 C (least precise)
F = 9/5(71.0) +32 = 127.8=128+32=160F
160F
How many sig figs does 0.0007680900 have?
7
A boy runs 5.098 miles in .897 hours. What is his average speed in miles/hour?
Use sig fig rules for mult/dividing
5.098 miles/.897 hr
5.68338907 miles/hour = 5.68 miles/hr (can only use least amount of sig figs when multiplying).
What is the difference between water with a lot of ice and water with a little bit of ice? (assume they are thoroughly mixed)?
NOTHING!!! Ice water will be a consistent temperature of 0 C or 32 F
Convert 0.00234 L to cm^3
Show work
Use sig figs
0.00234 L x 1000ml/1L = 2.34 ml = 2.34 cm^3
***Remember 1 ml = 1 cm^3
Solve. Use sig fig rules. Put answer in scientific notation.
Add 7.29801 X 10^3 L + 678934.76 mL
7298.01 L x 1000mL/1L = 7298010 mL
7298010mL + 678934.76 mL = 7976944.76mL=
7976944 mL = 7.976944 X 10^6 mL
0.982 x 10^-3
3
A student measures the mass of a box that is filled with marbles and finds it to be 458.0910 kg.
The teacher tells the class that the empty box weighed 76.09 kg.
What is the mass of the marbles?
(Use sig fig rules)
458.0910 kg
- 76.09 kg
________
382.001 kg
382.00 kg (least precise because sig fig subtraction rule)
What is the F equivalent to 0.00 K? use 3 sig figs
F = 9/5 C +32
C = 5/9 (F-32)
K = C + 273.15
C = K - 273.15
C = 0 - 273.15 C = -273.15
F = 9/5 (-273.15) + 32 = -459.67 F = -460 F