CH. 2 - MEASUREMENT III. Unit Conversions I II III (p. 40 - 42) A. SI Prefix Conversions 1. Find the difference between the exponents of the two prefixes. 2. Move the decimal that many places. To the left or right? A. SI Prefix Conversions 532 m NUMBER UNIT 0.532 km = _______ = NUMBER UNIT A. SI Prefix Conversions move right move left Prefix mega- Symbol M Factor 106 kilo- k 103 BASE UNIT --- 100 deci- d 10-1 centi- c 10-2 milli- m 10-3 micro- 10-6 nano- n 10-9 pico- p 10-12 A. SI Prefix Conversions 1) 20 cm = 0.2 ______________ m 32 2) 0.032 L = ______________ mL 3) 45 m = 45,000 ______________ nm 0.0805 4) 805 dm = ______________ km B. Dimensional Analysis The “Factor-Label” Method Units, or “labels” are canceled, or “factored” out g cm g 3 cm 3 B. Dimensional Analysis Steps: 1. Identify starting & ending units. 2. Line up conversion factors so units cancel. 3. Multiply all top numbers & divide by each bottom number. 4. Check units & answer. B. Dimensional Analysis Lining up conversion factors: 1 in = 2.54 cm =1 2.54 cm 2.54 cm 1 in = 2.54 cm 1= 1 in 1 in B. Dimensional Analysis 5) Your European hairdresser wants to cut your hair 8.0 cm shorter. How many inches will he be cutting off? cm in 8.0 cm 1 in 2.54 cm = 3.2 in B. Dimensional Analysis How many milliliters are in 1.00 quart of milk? qt mL 1.00 qt 1L 1000 mL 1.057 qt 1L = 946 mL B. Dimensional Analysis You have 1.5 pounds of gold. Find its volume in cm3 if the density of gold is 19.3 g/cm3. cm3 lb 1.5 lb 1 kg 1000 g 1 cm3 2.2 lb 1 kg 19.3 g = 35 cm3 B. Dimensional Analysis 6) Taft football needs 550 cm for a 1st down. How many yards is this? cm 550 cm yd 1 in 1 ft 1 yd 2.54 cm 12 in 3 ft = 6.0 yd B. Dimensional Analysis 7) A piece of wire is 1.3 m long. How many 1.5-cm pieces can be cut from this wire? cm pieces 1.3 m 100 cm 1m 1 piece 1.5 cm = 86 pieces B. Dimensional Analysis How many liters of water would fill a container that measures 75.0 in3? in3 L 75.0 in3 (2.54 cm)3 (1 in)3 1L 1000 cm3 = 1.23 L