1. Problem Solving fsUsing Conversion Factors
Chapter 1 Measurements
Problem Solving fsUsing Conversion Factors
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2. Initial and Final Units
1. A person has a height of 2.0 meters. What is that height in inches?
Initial unit = m Final unit = _______
2) Blood has a density of 0.05 g/mL. If a person lost 0.30 pints of blood at 18°C, how many ounces of blood would that be?
Initial = pints Final unit = _______
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3. How many minutes are in 2.5 hours?
Initial unit
2.5 hr
Conversion Final
factor unit
2.5 hr x min = min
1 hr
cancel Answer (2 SF)
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4. LecturePLUS Timberlake
Learning Check
A rattlesnake is 2.44 m long. How long is the snake in cm?
1) cm
2) 244 cm
3) 24.4 cm
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5. LecturePLUS Timberlake
Solution
A rattlesnake is 2.44 m long. How long is the snake in cm?
2) 244 cm
2.44 m x cm = 244 cm
1 m
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6. LecturePLUS Timberlake
Learning Check
How many seconds are in 1.4 days?
Unit plan: days hr min seconds
1.4 days x 24 hr x ??
1 day
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7. LecturePLUS Timberlake
Solution CF2
Unit plan: days hr min seconds
2 SF Exact
1.4 day x 24 hr x 60 min x 60 sec
1 day hr 1 min
= 1.2 x 105 sec
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8. LecturePLUS Timberlake
Unit Check
What is wrong with the following setup?
1.4 day x 1 day x min x 60 sec
24 hr hr min
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9. LecturePLUS Timberlake
Unit Check
1.4 day x 1 day x min x 60 sec
24 hr hr min
Units = day2/hr2 Not the final unit needed
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10. LecturePLUS Timberlake
Learning Check
An adult human has 4650 mL of blood. How many gallons of blood is that?
Unit plan: mL qt gallon
Equalities: 1 quart = 946 mL
1 gallon = 4 quarts
Your Setup:
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11. LecturePLUS Timberlake
Solution
Unit plan: mL qt gallon
Setup:
4650 mL x qt x 1 gal = gal
946 mL qt
3 SF SF exact SF
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12. Steps to Problem Solving
Read problem
Identify data
Write down a unit plan from the initial unit
to the desired unit
Select conversion factors
Change initial unit to desired unit
Cancel units and check
Do math on calculator
Give an answer using significant figures
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13. LecturePLUS Timberlake
Learning Check
If the ski pole is 3.0 feet in length, how long is the ski pole in mm?
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14. LecturePLUS Timberlake
Solution
3.0 ft x 12 in x cm x 10 mm =
1 ft in cm
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15. LecturePLUS Timberlake
Learning Check
If your pace on a treadmill is 65 meters per minute, how many seconds will it take for you to walk a distance of feet?
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16. LecturePLUS Timberlake
Solution
Initial
8450 ft x 12 in. x cm x 1 m
1 ft in cm
x 1 min x 60 sec = sec
65 m 1 min final (2 SF)
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