# Worksheet03-161F22-Key

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Worksheet 3 - In Class Practice - Chapter 1.7-10 1. How many significant figures are in the following? a) 4.1 x 10 6 km ______ 2 _______ b) 495,000 L 3-6 (min 3 and max 6) c) 0.000892 mg ________ 3 _______ d) 9.100 x 10 3 dm 3 _____ 4 _______ 2. Write the following in scientific notation : a) 8120.0 _____ 8.1200 x 10 3 _____________ b) 0.000589 _______ 5.89 x 10 -4 ____________ c) 91,030,000 (assume 5 significant figures) ________ 9.1030 x 10 7 __________ 3. Answer the following with the correct number of significant figures : a) 65.1 + 23.00 - 18 = 70.1 round to 70. (adding/subtracting use decimal place) b) 305.895 - 56.89 + 3.51 = 252.515 round to 252.52 c) 13 รท 16.5 X 0.11 = 0.8666667 round to 0.87 (addition and division use min sig figs) d) 0.00345 X 5.895 รท 34.129 = 0.000595908 round to 0.000596 or 5.96 x 10 -4 4. Convert the following: (Show work.) a) 15.57 ng to g ____ 15.57 ng ( 10 -9 g 1 ng ) = 1.557 x 10 -8 g __________________________ b) 0.00675 kg to g __ 0.0675 kg ( 10 3 g 1 kg )= 6.75 x 10 1 ? _____________________________ c) 8.43 x 10 -2 ML to ๏ญ L __ 8.43 x 10 -2 ML ( 10 6 L 1 ML )( ? ๐L 10 โ? ๐ ) = 8.43 x 10 10 ๐L ______________ d) 9.5 x 10 8 dm to km __ 9.5 x 10 8 dm( 10 -1 m 1 dm )( ? ?? 10 ? ? )= 9.5 x 10 4 ?? ______________ 5. a) DK Metcalf, wide receiver for the Seahawks, ran the 40-yard dash in 4.33 seconds. What is his speed in miles per hour (mph)? (Show your work) (1 mile= 5280 feet) ( 40. yard ?. ?? ? )( ? ?? ? ๐ฒ๐?? ) ( ? ???? ???? ?? ) ( ?? ? ? ??? )( ?? ??? ? ???? ) = 18.889 ???? ???? = 19 ???? ???? b) A grizzly bear can run up to 35 mph. Can DK Metcalf outrun a grizzly bear?______ NO ________
6. a) The B-2 Spirit, more commonly known as the stealth bomber flies at a maximum speed of 630 mph . Convert this speed to meters per second. ( 630 miles ???? )( ? ???? ?? ??? ) ( ? ??? ?? ? )( ? ๐๐ ?. ???? ????? ) ( 10 ? ? ? ?? ) = 281.62 ? ? = 280 ? ? (b) Sound travels at about 340 meters per second on a dry day when the temperature is around 20ยฐC. At max speed does a stealth bomber fly faster than the speed of sound? Does this make sense? โข The stealth bomber does not fly faster than the speed of sound. Any time something is faster than the speed of sound, there is a "sonic boom." In addition to being engineered to be "stealthy" it does not fly fast enough to create a sonic boom. 7. Dilantin is an anti-epileptic drug used to control seizures. A doctor orders 14.0 g of Dilantin for your patient. Dilantin is available in solution as 0.006 kg/10mL. What volume of this solution would you administer to the patient? ??. ? ?( 1 kg 10 ? ? ) ( ?? ๐๐ณ ?. ??? ๐๐ ) = 23.33 mL = 20 mL 8. In Europe, they use the notation of L/100 km (liters per 100 km) to note how much fuel a car utilizes. In the US, we generally talk about how efficient our vehicles are in units of miles per gallon (mpg). You find a vehicle labeled 5.0 L/100 km while looking for a car. What would this be in miles per gallon? (Show your work) ( 100 km ?. ? ๐ ) ( ?. ???? ????? ? ๐๐ ) ( ?. ????? ๐ ? ?๐? ) = 47.045 ????? ?๐? = ?? ????? ?๐?