convert unit rates. you and your friends want to have a movie marathon. all three movies last a...
TRANSCRIPT
Convert Unit Rates
You and your friends want to have a movie marathon. All three movies last a total of 390 min. How many hours will it take to watch all three movies?
60min390 = 6.5 min
How do we get the unit to change to hours?
We need to use dimensional analysis.
Not in notes
Unit Ratio (conversion factors)-
Dimensional analysis - Process using unit ratios (conversion factors) to convert between units.
A ratio where the numerator and denominator are equivalent measurements.
m
cm
lb
oz
ft
in
1
100
1
16
1
12
Conversion factors and dimensional analysis make comparing different units much easier. These conversions are necessary in many calculations in your physical science and chemistry classes.
Not in notes
Fill in the Missing Numbers1 ft = ____ in
1 m = ____ cm
1 lb = ____ oz
1 min = ____ sec
1 hr = ____ min
1 day = ___ hrs
1 yr = ____ mo
1 yr = ___ wks
12
100
16
60
60
1 km =_____ m
1 mi = _____ yd
1 yd = ___ ft
1 cm = ___ mm
1 gal = ____ qt
1 qt = ___ pt
1 pt = ___ c
1 wk = ___days
1 c = _____ fl oz
1 T = _____ lb
1 kg = ____ g
1 L = ______ mL
1 yr = ____ mo
1 g = ____ mg
1000
1760
3
10
4
24
12
5216
2000
2
2
71000
12
1000 1000
Dimensional analysis process
Unit you have X Conversion factor = Unit you want
4
3
7
4X
Remember : we can cancel with multiplying fractions
1
17
3
we can do the same with units.
Hour
Minute
Minute
Second
Hour
Second
You and your friends want to have a movie marathon. All three movies last a total of 390 min. How many hours will it take to watch all three movies?
1
min390X 60
1
minhr
60
390 hr6.5 hrs
Not in notes
EX 1) Jeff is 72 in. tall. How tall is Jeff in ft.?
Convert Units by dimensional analysis
1
72 in12
1
12
72 ftft6
Step 1: Write your ratio in fraction form.
Step 2: Choose your conversion factor that will cancel one unit and keep the wanted unit.
Step 3: Simplify and multiply.
in
ft=
EX 2) Martha needs to know how many inches in 8 yards of fabric.
1
8yd1
3
1
288in.288 inyd
ft=X
1
12
ft
in
EX 3) A copier copied 4080 sheets per hour. How many sheets were copied in 1 minute?
hr
sheets
1
4080
60
1
min60
4080 sheets
min
Sheetsmin
hr=
1
68=
How many minutes in a year?
Answer
525,600 min.
notes
Convert Unit RatesDate ________
Fill in the Missing Numbers1 ft = ____ in
1 m = ____ cm
1 lb = ____ oz
1 min = ____ sec
1 hr = ____ min
1 day = ___ hrs
1 yr = ____ mo
1 yr = ___ wks
1 km =_____ m
1 mi = _____ yd
1 yd = ___ ft
1 cm = ___ mm
1 gal = ____ qt
1 qt = ___ pt
1 pt = ___ c
1 wk = ___days
1 c = _____ fl oz
1 T = _____ lb
1 kg = ____ g
1 L = ______ mL
1 yr = ____ mo
1 g = ____ mg
EX 1) Jeff is ___ in. tall. How tall is Jeff in ft.?
Convert Units by dimensional analysis
Step 1: Write your ratio in ________ ____.
Step 2: Choose your __________ ______ that will cancel one unit and keep the wanted unit.
Step 3:
EX 2) Martha needs to know how many inches in ___ yards of fabric.
EX 3) A copier copied ____ sheets per hour. How many sheets were copied in 1 minute?