Worksheet: Conversions Complete each of the following. Show all work and use correct sig figs and rounding rules. 1. This lovely new building (built in 2007) is four stories tall. If each story is 10’4” tall, what is the height in centimeters? 2. Nelson is cruising to BHHS at 21.8 mph. What is his speed in millimeters per second? 3. Allison has contracted the Swine flu—one of many reasons you should never hang out with pigs. Her mother says she has a 102.1o fever. Knowing that this is 38.9 oC, what is her temperature in K? 4. Julian de los Prados—famous around the world for his lightning speed—is chasing a soccer ball at 5 ft/min. What is his speed in meters per second? 5. Freefall at Magic Mountain drops its victims (I mean riders) 225 feet. How many mm? 6. A bullet travels at about 7500 inches each second. How many km will it travel in a day? 7. If there are a dozen boxes of grapes in a crate, each box contains three bunches and each bunch contains 29 grapes, how many grapes are in eigheen crates? 8. Mr. Kobe’s aquarium filter cleans about 275 cm3 of water each minute. How fast is this in dm3 per hour? How long will it take to clean a tank that is 75 cm by 40 cm by 28 cm? 9. A calorie is equivalent to 4.18 Joules of energy. We mistakenly refer to the measurement of the food we ingest as being a calorie. That unit is actually a kilocalorie. Knowing this, how much energy (in joules) does the average person consuming 3500 “calories” gain? 10. A person runs 3000 inches. How many meters has this person run? 11. School lasts 180 days. If the average school day is 6 hours and 45 minutes long, how many seconds of your life are spent in school each year? (if this depresses you, figure out how many seconds of your life are spent OUTSIDE of school during the same time period ;-) 12. Bella—finally able to escape her stalker vampire boyfriend—measures a block and finds its mass to be 9.43 grams, its dimensions to be 5.31 cm by .51 cm by 1.09 cm. What is its density? Is the block made of aluminum? Explain how you can tell. If the block is actually lead, what is Bella’s percent error? 13. Do problems 85-87 on page 97
Answers: (to some of the problems AND not in the same order ;-) 305 1260 0.03 19, 000 9750 4 312.1 68600 42000 1.6 x 10 16.5 7 1.5 x 10 72 4400000 no; too dense 80
.804 .69 to .789 3.19
ANSWER KEY: 1. 10’4” = 124 inches 4 floors 2.54 cm = 1, 259.84 cm = 1260 cm tall floor inch 2. 21.8 miles 5280 feet 12 inches 2.54 cm 10 mm 1 hour hour mile 1 foot inch 1 cm 60 min
1 min = 9, 745.472 = 9750 60 sec mm/s
3. 38.9 oC + 273.15 = 312.05 = 312.1 K 4. 5 feet min
12 in 1 foot
2.54 cm 1 m 1 min = .0254 = .03 m/s 1 in 100 cm 60 sec
5. 225 feet 12 in 2.54 cm = 68580 = 68600 cm 1 foot 1 in 6. one day 24 hrs 60 min 60 sec 7500 inches 2.54 cm 1 m 1 km = 1645.92 day hr min sec 1 in 100 cm 1000 m 1.6 x 104 7. 18 crates 12 boxes 3 bunches 29 grapes = 18, 792 = 19, 000 grapes crate box bunch 8. 275 cm3 60 min min 1 hr 9. 3500 kcal
1 dm 10 cm
1000 cal 1 kcal
10. 3000 inches
3
= 16.5 dm3/hr 75 x 40 x 28 = 84, 000 cm3 84,000 cm3 ÷ 275 cm3/min = 305.45 = 305 min
4.18 Joules = 14, 630, 000 = 15, 000, 000 Joules = 1.5 x 107 J cal
2.54 cm 1 meter = 76.2 = 80 meters in 100 cm 11. 180 days 6.75 hrs 60 min 60 sec = 4, 374, 000 = 4, 400, 000 sec = 4.4 x 106 sec 1day 1 hr 1 min 12. v = 5.31 cm x .51 cm x 1.09 cm = 2.95 cm3 m = 9.43 g d = m = 9.43 g = 3.19 g/cm3; this is not aluminum—it is too dense v 2.95 cm3 % error = theoretical – experimental x 100% = 11.4 – 3.19 x 100% = 8.205 x 100% theoretical 11.4 11.4 = 71.9769342 = 72% error 13. 85. dethanol = .789 g/cm3, dgasoline = .66 to .69 range: .69 to .789 g/cm3 cm3 = 42016.80672 = 42000 cm3 86. v = m = 50.0 g d 1.19 x 10-3 87. v = m = 158 g cm3 = 158 cm3 in the flask d 1.000 g = .804 g/cm3 d = m = 127 g v 158 cm3
