Chapter 1 Measurements

1
Chapter 1Measurements

• Problem Solving fsUsing Conversion Factors

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 18C, how many
  ounces of blood would that be?
• Initial pints Final unit _______

3
How many minutes are in 2.5 hours?

• Initial unit
• 2.5 hr
• Conversion Final
• factor unit
• 2.5 hr x 60 min 150 min
• 1 hr
• cancel Answer (2 SF)

4
Learning Check

• A rattlesnake is 2.44 m long. How long is the
  snake in cm?
• 1) 2440 cm
• 2) 244 cm
• 3) 24.4 cm

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Solution

• A rattlesnake is 2.44 m long. How long is the
  snake in cm?
• 2) 244 cm
• 2.44 m x 100 cm 244 cm
• 1 m

6
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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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 1 hr 1 min
• 1.2 x 105 sec

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Unit Check

• What is wrong with the following setup?
• 1.4 day x 1 day x 60 min x 60
  sec
• 24 hr 1 hr
  1 min

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Unit Check

• 1.4 day x 1 day x 60 min x 60
  sec
• 24 hr 1 hr
  1 min
• Units day2/hr2 Not the final unit needed

10
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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Solution

• Unit plan mL qt
  gallon
• Setup
• 4650 mL x 1 qt x 1 gal
  1.23 gal
• 946 mL 4 qt
• 3 SF 3 SF exact
  3 SF

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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

13
Learning Check

• If the ski pole is 3.0 feet in length, how long
  is the ski pole in mm?

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Solution

• 3.0 ft x 12 in x 2.54 cm x 10 mm
• 1 ft 1 in.
  1 cm

15
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 8450 feet?

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Solution

• Initial
• 8450 ft x 12 in. x 2.54 cm x 1 m
  
• 1 ft 1 in. 100 cm
• x 1 min x 60 sec 2400 sec
• 65 m 1 min final (2 SF)