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Chapter 1 Measurements. Problem Solving fsUsing Conversion Factors. 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 = _______
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Chapter 1Measurements Problem Solving fsUsing Conversion Factors LecturePLUS Timberlake
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 = _______ LecturePLUS Timberlake
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) LecturePLUS Timberlake
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 LecturePLUS Timberlake
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 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 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 1 hr 1 min = 1.2 x 105 sec LecturePLUS Timberlake
Unit Check What iswrong with the following setup? 1.4 day x 1 day x 60 min x 60 sec 24 hr 1 hr 1 min LecturePLUS Timberlake
Unit Check 1.4 day x 1 day x 60 min x 60 sec 24 hr 1 hr 1 min Units = day2/hr2Not the final unit needed 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: LecturePLUS Timberlake
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 LecturePLUS Timberlake
Steps to Problem Solving • Read problem • Identify data and Units • 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 LecturePLUS Timberlake
Learning Check If the ski pole is 3.0 feet in length, how long is the ski pole in mm? LecturePLUS Timberlake
Solution 3.0 ft x 12 in x 2.54 cm x 10 mm = 1 ft 1 in. 1 cm 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 8450 feet? LecturePLUS Timberlake
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) LecturePLUS Timberlake