Problem of the Day
Write the conversion factor needed to convert the following…
1) 172 ounces = _____ pounds
Write the conversion factor needed to convert the following…
2) 2.4 kL = _____ L
5-6: Dimensional Analysis
Course 3 book; Section 5-3
Using Conversion Ratios to
Convert Units of Measurement
Vocabulary
Conversion Factor
A fraction whose numerator and
denominators represent the same quantity
but use different units
To write a Conversion Ratio…
I.
Find the Ratio that can be multiplied
with the original Ratio that will…
cancel the original unit, while
introducing the desired unit.
To solve problems using Conversion
Ratios…
I.
Write the original units as a Ratio…
II.
Write the conversion Ratio, so the original unit
cancels, through cross cancellation, while introducing
the desired unit.
III.
Multiply the two Ratios… include the newly
converted units in your answer.
IV.
Find the Unit Ratio of the newly Converted Ratio.
Examples
Find the appropriate Conversion Ratio to
each conversion.
A) Feet to Yards
Original unit is Feet; Converting to Yards
Examples
Find the appropriate Conversion Ratio to
each conversion.
A) Feet to Yards
Original unit is Feet; Converting to Yards
1yd
3 ft
Examples
Find the appropriate Conversion Ratio to
each conversion.
B) Pounds to Ounces
Original unit is Pounds; converting to Ounces
Examples
Find the appropriate Conversion Ratio to
each conversion.
B) Pounds to Ounces
Original unit is Pounds; converting to Ounces
16 oz
1lb
Examples
C)
The average American uses 580 pounds of paper
per year. Find the number of pounds of paper the
average American uses per month. Round answer
to the nearest tenth.
Examples
C)
The average American uses 580 pounds of paper
per year. Find the number of pounds of paper the
average American uses per month. Round answer
to the nearest tenth.
580lbs
1yr
Examples
C)
The average American uses 580 pounds of paper
per year. Find the number of pounds of paper the
average American uses per month. Round answer
to the nearest tenth.
580lbs
1yr
580pounds 1year
580pounds
x

1year
12m onths 12m onths
Examples
C)
The average American uses 580 pounds of paper
per year. Find the number of pounds of paper the
average American uses per month. Round answer
to the nearest tenth.
580lbs
1yr
580pounds 1year
580pounds
x

1year
12m onths 12m onths
580 pounds  12 48.3 pounds

12 months  12
1month
Examples
D)
A car traveled 60 miles in 2 hours. How many feet
per second was the car traveling?
Examples
D)
A car traveled 60 miles in 2 hours. How many feet
per second was the car traveling?
60 miles
2hrs
Examples
D)
A car traveled 60 miles in 2 hours. How many feet
per second was the car traveling?
60 miles
2hrs
60 miles
1hour
60 miles
x

2hours 3600 sec onds 7200 sec onds
Examples
D)
A car traveled 60 miles in 2 hours. How many feet
per second was the car traveling?
60 miles
2hrs
60 miles
1hour
60 miles
x

2hours 3600 sec onds 7200 sec onds
60 miles
5280 feet
316 ,800 feet
x

7200 sec onds
1mile
7200 sec onds
Examples
D)
A car traveled 60 miles in 2 hours. How many feet
per second was the car traveling?
60 miles
2hrs
60 miles
1hour
60 miles
x

2hours 3600 sec onds 7200 sec onds
60 miles
5280 feet
316 ,800 feet
x

7200 sec onds
1mile
7200 sec onds
316 ,800 feet  7200
44 feet

7200 sec onds  7200 1sec ond
44 feet per second
Examples
E)
A strobe lamp can be used to measure the speed of
an object. The lamp flashes every 1/100 of a
second. A camera records the object moving 52 cm
between flashes. How fast is the object moving in
m/s?
Examples
E)
A strobe lamp can be used to measure the speed of
an object. The lamp flashes every 1/100 of a
second. A camera records the object moving 52 cm
between flashes. How fast is the object moving in
m/s?
52cm
1
sec
100
Examples
E)
A strobe lamp can be used to measure the speed of
an object. The lamp flashes every 1/100 of a
second. A camera records the object moving 52 cm
between flashes. How fast is the object moving in
m/s?
52cm
1m
52 m
x

1
100 cm 1sec
sec
100
F) Usain Bolt won the gold medal in the Beijing Olympics
by running the 100-meter sprint in 9.69 seconds. How
fast was Bolt running in Miles per Hour? (Hint: 1 meter
is approximately 3.28 feet).
F) Usain Bolt won the gold medal in the Beijing Olympics
by running the 100-meter sprint in 9.69 seconds. How
fast was Bolt running in Miles per Hour? (Hint: 1 meter
is approximately 3.28 feet).
100m
9.69 sec
F) Usain Bolt won the gold medal in the Beijing Olympics
by running the 100-meter sprint in 9.69 seconds. How
fast was Bolt running in Miles per Hour? (Hint: 1 meter
is approximately 3.28 feet).
100m
9.69 sec
100 m
328 ft

9.69 sec 9.69 sec
F) Usain Bolt won the gold medal in the Beijing Olympics
by running the 100-meter sprint in 9.69 seconds. How
fast was Bolt running in Miles per Hour? (Hint: 1 meter
is approximately 3.28 feet).
100m
9.69 sec
100 m
328 ft

9.69 sec 9.69 sec
328 ft
1m ile
328m iles


9.69sec 5,280 ft 51,163.3 sec
F) Usain Bolt won the gold medal in the Beijing Olympics
by running the 100-meter sprint in 9.69 seconds. How
fast was Bolt running in Miles per Hour? (Hint: 1 meter
is approximately 3.28 feet).
100m
9.69 sec
100 m
328 ft

9.69 sec 9.69 sec
328 ft
1m ile
328m iles


9.69sec 5,280 ft 51,163.3 sec
328m iles 3600sec 1,180,800m iles


51,163.3 sec
1hr
51,163.3hrs
F) Usain Bolt won the gold medal in the Beijing Olympics
by running the 100-meter sprint in 9.69 seconds. How
fast was Bolt running in Miles per Hour? (Hint: 1 meter
is approximately 3.28 feet).
100m
9.69 sec
100 m
328 ft

9.69 sec 9.69 sec
328 ft
1m ile
328m iles


9.69sec 5,280 ft 51,163.3 sec
328m iles 3600sec 1,180,800m iles


51,163.3 sec
1hr
51,163.3hrs
1,180,800m iles 51,163.3 23.079043m iles

51,163.3hrs  51,163.3
1hour
Approximately 23 miles per hour