# 2.1: Homework Chapter 2


Questions

2)     Define significant figures. Why are they important?

3)     Define the different types of zeros found in a number and explain whether or not they are significant.

4)     Give the two conversion factors you can construct using each pair of units.

c)      meters and kilometers

b)     liters and microliters

a)     seconds and milliseconds

5)     In general, how can you identify whether or not you have written the correct conversion factor for the problem?

6)     Construct a conversion factor that can convert from one unit to the other in each pair of units.

a)     meter to km

b)     inch to cm

c)      pounds to kilogram

Scientific Notation

7)     Convert each number into scientific notation.

a)      100,000,000

b)     0.0004970

c)      30.01

d)     2500

8)     Convert each number into scientific notation.

a.       304,300,000

b.      0.0004

c.       1000.

d.      0.345

9)     Convert each number into scientific notation.

a.       736,350

b.      0.0042

c.       2500

d.      0.478

10) Convert each number into decimal notation.

a.    7.42 x 103

b.    1.3 x 10-3

c.     1.5 x 106

d.    1.5147 x 10‑5

11) Convert each number into decimal notation.

a.    8.62 x 104

b.    5.5 x 10-3

c.    1.02 x 10-6

d.    6.03 x 10-10

12) Convert each number into decimal notation.

a.    8.35 x 106

b.    6.3 x 10-4

c.     1.8 x 106

d.     7.24 x 10-6

13) Fill in the blanks.

 Scientific Notation Decimal Notation a) 4.7 x103 b) 7,410. c) 9.3 x 10-4 d) 0.0045

14) Fill in the blanks.

 Scientific Notation Decimal Notation a) 5.36 x106 b) 1,120.0 c) 1.3 x 10-2 d) 0.010

15) Fill in the blanks.

 Scientific Notation Decimal Notation a) 8.4 x 105 b) 513 c) 6.30 x 10-6 d) 0.250

Significant Figures

16. Use each diagram to report a measurement to the proper number of significant figures.

17) Use each diagram to report a measurement to the proper number of significant figures.

18) Use each diagram to report a measurement to the proper number of significant figures.

19) Give the number of significant figures in each. Identify the rule for each.

a) 0.000140500 s

b) 630,001 kg

c) 155.000 in

d) 0.0745 m

20) Give the number of significant figures in each. Identify the rule for each.

a) 0.000250600 s

b) 720,055 kg

c) 589.560 in

d) 0.0856 m

21)  Give the number of significant figures in each. Identify the rule for each.

a) 0.00540500 s

b) 890,024 kg

c) 729.770 in

d) 0.0961 m

22) How many significant figures are in each number?

a)     1.05

b)     9,500

c)      0.0004505

d)     7563

23) How many significant figures are in each number?

a.       0.00045050

b.      7.210 × 106

c.       5.005 × 10−6

d.      4861

24) How many significant figures are in each number?

a.  0.052010

b. 0.3940

c. 8200

d. 8563

Rounding

25) Round each number to three significant figures.

a. 24.632

b. 0.34244

c. 43,539

d. 6.9978 x 106

26) Round each number to three significant figures.

a. 35.743

b. 0.45355

c. 54640

d.  7.0089 x 106

27) Round each number to three significant figures.

a. 56.45

b. 8.90443 × 108

c. 1,000,000

d. 0.9841

28) Determine if each number is rounded correctly to three significant figures. For any items that are incorrect, correct them.

a. 3.459 x 103 to 3.5 x 103

b. 4.874 x 103 to 50

c. 87.42 to 87.4

d. 0.09853 to 0.010

29) Determine if each number is rounded correctly to three significant figures. For any items that are incorrect, correct them.

a. 4.560 x 103 to 4.5 x 103

b. 8.514 x 103 to 85

c. 93.72 to 93.7

d. 0.05312 to 0.053

30) Determine if each number is rounded correctly to three significant figures. For any items that are incorrect, correct them.

a. 5.670 x 103 to 5.7 x 103

b. 5.783 x 103 to 60

c. 87.42 to 87.4

d. 0.023541 to 0.024

31) Complete the table.

 Number Rounded to 4 Significant Figures Rounded to 2 Significant Figures Rounded to 1 Significant Figure a. 53.53229 53.53 54 5 x 101 b.216.3535 c. 0.36682 d. 0.00888881

32) Complete the table.

 Number Rounded to 4 Significant Figures Rounded to 2 Significant Figures Rounded to 1 Significant Figure a. 64.64320 64.64 64 6 x 101 b.335.4545 c. 0.54156 d. 0.00777772

33) Complete the table.

 Number Rounded to 4 Significant Figures Rounded to 2 Significant Figures Rounded to 1 Significant Figure a. 82.6268 82.63 83 8 x 101 b.654.8545 c. 0.75126 d. 0.00777774

Significant Figures in Calculations

34) Determine if each calculation has the correct number of significant figures. For any items that are incorrect, correct them.

a) 45.3254 x 59.00205 = 2674.3

b) 0.00830 x 47.351 = 0.039

c) 0.008070 / 5018.3 = 1.61811 x 10-6

d) 0.04541 x 7143.5 =  324.39

35) Determine if each calculation has the correct number of significant figures. For any items that are incorrect, correct them.

a) 105.34 x 47.334532 = 4986.22

b) 0.047 x 23.3544 = 1.098

c) 5.5225 / 503.455 = 0.010969

d) 0.000154*1002.2 =  0.15

36) Determine if each calculation has the correct number of significant figures. For any items that are incorrect, correct them.

a) 17.354 x 875.214 = 15100

b) 0.0035 x 20.0456 = 0.07

c) 0.00486 / 40.8954 = 0.000119

d) 0.00225 * 2458.3 = 5.53

37) Determine if each calculation has the correct number of significant figures. For any items that are incorrect, correct them.

a)          5.8 + 63.09 – 14 = 54.9

b)         4301 – 2900.14 + 1.6 = 1402

c)          0.00354 + 0.86 = 0.863

d)         0.00974 – 0.008 = 0.00074

38) Determine if each calculation has the correct number of significant figures. For any items that are incorrect, correct them.

a)          7.4 + 73.07 – 24 = 56.5

b)         5323 – 3914.24 + 0.7 = 1409

c)          0.00725 + 0.35 = 0.357

d)         0.00653 – 0.003 = 0.00353

39) Determine if each calculation has the correct number of significant figures. For any items that are incorrect, correct them.

a)          3.5 + 94.04 – 50 = 47.5

b)         8206 – 5614.25 + 5.5 = 2597.25

c)          0.00354 + 0.864 = 0.868

d)         0.01874 – 0.010 = 0.00874

40) Determine if each calculation has the correct number of significant figures. For any items that are incorrect, correct them.

a.  (9.95 + 3.09) / 7.40000 = 1.762

b. (1045.3 – 1.4) x 1.604 = 1674

c. (749.40 + 6.7) / 4.54 = 1.6 x 102

d.  (845 / 301457) + 5.000198 = 5.00

41) Determine if each calculation has the correct number of significant figures. For any items that are incorrect, correct them.

a. (8.65 + 2.85) / 8.96000 = 1.283

b. (2252.5 – 2.8) x 2.765 = 6220

c. (760.55 + 8.8) / 5.64 = 1.4 x 102

d.  (945 / 54147) + 4.51400014 = 4.53

42) Determine if each calculation has the correct number of significant figures. For any items that are incorrect, correct them.

a. (1.24 + 3.14) / 4.54000 = 0.96

b. (3251 – 3.6) x 6.54 = 21238

c. (651.25 + 6.3) / 6.55 = 100

d.  (360 /64025) + 5.4100087 = 5.41

Unit Conversion

43) Convert the following metric quantities into the indicated units. Identify the number of significant figures in each answer.

a.          1000. g into milligrams

b.          6981 nm into meters

c.           15 mL into liters

d)         345 cm to millimeters

44) Convert the following metric quantities into the indicated units. Identify the number of significant figures in each answer.

a.          8541 g into mg

b.          7896 nm into m

c.           25 kL into L

d.          62 cm to mm

45) Convert the following metric quantities into the indicated units. Identify the number of significant figures in each answer.

a.     34 kg to g

b.     7539.34 nm to km

c.     36 L into cL

d.     109 cm to mm

46) Use English-to-Metric and Metric-to-English conversion factors to calculate the following:

a) 87.6 ft into centimeters

b) 557 yd to meters

c) 645 feet to centimeters

d) 7.0 inch to centimeters

47) Use English-to-Metric and Metric-to-English conversion factors to calculate the following:

a) 90.7 ft into mm

b) 14.8 lb to kg

c) 400. m to mi

d) 12.0 in to cm

48) Use English-to-Metric and Metric-to-English conversion factors to calculate the following:

a) 71.3 ft to mm

b) 15.2 lbs to kg

c) 520. m to mi

d) 8.0 in to cm

49) Fill in the blank to complete the table.

 m km mm nm pm 6.02 x10-5 s 6.02 x 10-2 mm 25.3 pm 225 nm 8.22 x 10-3 km 4.2 x 105 mm

50) Fill in the blank to complete the table.

 m km mm nm pm 5.36 x10-5 s 5.36 x 10-2 mm 18.7 pm 345 nm 6.33 x 10-3 km 5.5 x 105 mm

51) Fill in the blank to complete the table.

 m km mm nm pm 1.88 x10-5 s 1.88 x 10-2 mm 14.3 pm 365 nm 6.34 x 10-3 km 6.9 x 105 mm

Unit Raised to a Power

52) Perform each conversion.

a) 1.2 ft2 = _____in2

b) 1.2 yd2 = _______ft2

c) 1.2 m3 = _______ yd3

53) Perform each conversion.

a) 2.4 ft2 = _____in2

b) 2.4 yd2 = _______ft2

c) 2.4 m3 = _______ yd3

54) Perform each conversion.

a) 3.5 ft2 = _____in2

b) 3.5 yd2 = _______ft2

c) 35 m3 = _______ yd3

55) A pizza has an area of 3.44 m2. Convert the pizza’s area to each of the following units.

a) in2

b) mm2

c) km2

56) A pizza has an area of 2.50 m2. Convert the pizza’s area to each of the following units.

a) in2

b) mm2

c) km2

57) A pizza has an area of 13.5 m2. Convert the pizza’s area to each of the following units.

a) in2

b) mm2

c) km2

Density

58) A copper strip has a mass of 4.67 g and a volume of 0.523 cm3. What is the density of the copper strip? Is the strip pure copper?

59) A lead strip has a mass of 7.41 g and a volume of 0.654 cm3. What is the density of the lead strip? Is the strip pure lead?

60) A silver ingot has a mass of 70.34 g and a volume of 8.5 cm3. What is the density of the ingot? Is the ingot pure silver?

61) Given that the density of gold is 19.3 g/cm3,

a) Determine the mass of gold (in grams) in an ingot with a volume of 121 cm3.

b) Determine the volume of gold (in cm3) in an ingot with a mass of 1354 g.

62) Given that the density of Cu is 8.93 g/cm3,

a) Determine the mass of copper (in grams) in a copper strip with a volume of 433.0 cm3.

b) Determine the volume of copper (in cm3) in a copper strip with a mass of 502.34 grams.

63) Given that the density of lead is 11.34 g/cm3,

a) Determine the mass of lead (in grams) in a lead block with a volume of  607.9 cm3.

b) Determine the volume of lead (in cm3) in a lead block with a mass of 802.35 grams.

Cumulative Problems

64) If the walls in a room are 955 square feet in area, and a gallon of paint covers 15 square yards, how many gallons of paint are needed to paint the walls in the room? (3 ft = 1 yd)

65) Gas is sold for \$1.399 per liter in Toronto, Canada. Your car needs 12.00 gallons. How much will your credit card be charged in Canadian dollars (minus tax)?

66) If an object has a density of 8.65 g/cm3, what is its density in units of kg/m3?

67) Water is being pumped out of a reservoir at a rate of 2.54 liters per 15.0 seconds. If the reservoir contains 1.0500 x 106 gallons of water, how many hours will it take to empty it?

68) The mass of an average blueberry is 0.75 g and the mass of an automobile is 2,010.3 kg. Find the number of automobiles whose total mass is the same as 1.0 x 1010 blueberries?

69) Tom and Mary both have farms. Tom raises chickens for eggs while Mary plants apples. 3.00 lb of apples can be exchanged with 1 dozen eggs. If Tom has 130. eggs to exchange with Mary, how many pounds of apples will he get?

70) Calculate the number of seconds in 1.00 year.

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