2.E: Measurements (Exercises)
 Page ID
 64977
2.1: Expressing Numbers
1. Express these numbers in scientific notation.
 56.9
 563,100
 0.0804
 0.00000667
2. Express these numbers in scientific notation.
 −890,000
 602,000,000,000
 0.0000004099
 0.000000000000011
3. Express these numbers in scientific notation.
 0.00656
 65,600
 4,567,000
 0.000005507
4. Express these numbers in scientific notation.
 65
 −321.09
 0.000077099
 0.000000000218
5. Express these numbers in standard notation.
 1.381 × 10^{5}
 5.22 × 10^{−7}
 9.998 × 10^{4}
 7.11 × 10^{−2}
 9.18 × 10^{2}
 3.09 × 10^{−10}
7. Express these numbers in standard notation.
 8.09 × 10^{0}
 3.088 × 10^{−5}
 −4.239 × 10^{2}
8. Express these numbers in standard notation.
 2.87 × 10^{−8}
 1.78 × 10^{11}
 1.381 × 10^{−23}
9. These numbers are not written in proper scientific notation. Rewrite them so that they are in proper scientific notation.
 72.44 × 10^{3}
 9,943 × 10^{−5}
 588,399 × 10^{2}
10. These numbers are not written in proper scientific notation. Rewrite them so that they are in proper scientific notation.
 0.000077 × 10^{−7}
 0.000111 × 10^{8}
 602,000 × 10^{18}
 345.1 × 10^{2}
 0.234 × 10^{−3}
 1,800 × 10^{−2}
12. These numbers are not written in proper scientific notation. Rewrite them so that they are in proper scientific notation.
 8,099 × 10^{−8}
 34.5 × 10^{0}
 0.000332 × 10^{4}
13. Write these numbers in scientific notation by counting the number of places the decimal point is moved.
 123,456.78
 98,490
 0.000000445
14. Write these numbers in scientific notation by counting the number of places the decimal point is moved.
 0.000552
 1,987
 0.00000000887
15. Use your calculator to evaluate these expressions. Express the final answer in proper scientific notation.
 456 × (7.4 × 10^{8}) = ?
 (3.02 × 10^{5}) ÷ (9.04 × 10^{15}) = ?
 0.0044 × 0.000833 = ?
16. Use your calculator to evaluate these expressions. Express the final answer in proper scientific notation.
 98,000 × 23,000 = ?
 98,000 ÷ 23,000 = ?
 (4.6 × 10^{−5}) × (2.09 × 10^{3}) = ?
17. Use your calculator to evaluate these expressions. Express the final answer in proper scientific notation.
 45 × 132 ÷ 882 = ?
 [(6.37 × 10^{4}) × (8.44 × 10^{−4})] ÷ (3.2209 × 10^{15}) = ?
18. Use your calculator to evaluate these expressions. Express the final answer in proper scientific notation.
 (9.09 × 10^{8}) ÷ [(6.33 × 10^{9}) × (4.066 × 10^{−7})] = ?
 9,345 × 34.866 ÷ 0.00665 = ?
Answers

 5.69 × 10^{1}
 5.631 × 10^{5}
 8.04 × 10^{−2}
 6.67 × 10^{−6}

 6.56 × 10^{−3}
 6.56 × 10^{4}
 4.567 × 10^{6}
 5.507 × 10^{−6}

 138,100
 0.000000522
 99,980

 8.09
 0.00003088
 −423.9

 7.244 × 10^{4}
 9.943 × 10^{−2}
 5.88399 × 10^{7}

 3.451 × 10^{4}
 2.34 × 10^{−4}
 1.8 × 10^{1}

 1.2345678 × 10^{5}
 9.849 × 10^{4}
 4.45 × 10^{−7}

 3.3744 × 10^{11}
 3.3407 × 10^{−11}
 3.665 × 10^{−6}

 6.7346 × 10^{0}
 1.6691 × 10^{−14}
2.2: Expressing Units
 Identify the unit in each quantity.
 2 boxes of crayons
 3.5 grams of gold


Identify the unit in each quantity.
 32 oz of cheddar cheese
 0.045 cm^{3} of water



Identify the unit in each quantity.
 9.58 s (the current world record in the 100 m dash)
 6.14 m (the current world record in the pole vault)



Identify the unit in each quantity.
 2 dozen eggs
 2.4 km/s (the escape velocity of the moon, which is the velocity you need at the surface to escape the moon's gravity)



Indicate what multiplier each prefix represents.
 k
 m
 M



Indicate what multiplier each prefix represents.
 c
 G
 μ



Give the prefix that represents each multiplier.
 1/1,000th ×
 1,000 ×
 1,000,000,000 ×



Give the prefix that represents each multiplier.
 1/1,000,000,000th ×
 1/100th ×
 1,000,000 ×


Complete the following table with the missing information.
Unit Abbreviation kilosecond mL Mg centimeter 
Complete the following table with the missing information.
Unit Abbreviation kilometer per second second cm^{3} μL nanosecond


Express each quantity in a more appropriate unit. There may be more than one acceptable answer.
 3.44 × 10^{−6} s
 3,500 L
 0.045 m



Express each quantity in a more appropriate unit. There may be more than one acceptable answer.
 0.000066 m/s (Hint: you need consider only the unit in the numerator.)
 4.66 × 10^{6} s
 7,654 L



Express each quantity in a more appropriate unit. There may be more than one acceptable answer.
 43,600 mL
 0.0000044 m
 1,438 ms



Express each quantity in a more appropriate unit. There may be more than one acceptable answer.
 0.000000345 m^{3}
 47,000,000 mm^{3}
 0.00665 L


Multiplicative prefixes are used for other units as well, such as computer memory. The basic unit of computer memory is the byte (b). What is the unit for one million bytes?

You may have heard the terms microscale or nanoscale to represent the sizes of small objects. What units of length do you think are useful at these scales? What fractions of the fundamental unit of length are these units?

Acceleration is defined as a change in velocity per time. Propose a unit for acceleration in terms of the fundamental SI units.
Density is defined as the mass of an object divided by its volume. Propose a unit of density in terms of the fundamental SI units.
Answers
 boxes of crayons
 grams of gold


 seconds
 meters


 1,000 ×
 1/1,000 ×
 1,000,000 ×


 milli
 kilo
 giga


 Unit
Abbreviation  kilosecond
 ks
 milliliter
 mL
 megagram
 Mg
 centimeter
 cm

 3.44 μs
 3.5 kL
 4.5 cm



 43.6 L
 4.4 µm
 1.438 s


megabytes (Mb)


meters/second^{2}
2.3: Significant Figures
 Express each measurement to the correct number of significant figures.
 Express each measurement to the correct number of significant figures.
 How many significant figures do these numbers have?
 23
 23.0
 0.00023
 0.0002302


How many significant figures do these numbers have?
 5.44 × 10^{8}
 1.008 × 10^{−5}
 43.09
 0.0000001381



How many significant figures do these numbers have?
 765,890
 765,890.0
 1.2000 × 10^{5}
 0.0005060



How many significant figures do these numbers have?
 0.009
 0.0000009
 65,444
 65,040



Compute and express each answer with the proper number of significant figures, rounding as necessary.
 56.0 + 3.44 = ?
 0.00665 + 1.004 = ?
 45.99 − 32.8 = ?
 45.99 − 32.8 + 75.02 = ?



Compute and express each answer with the proper number of significant figures, rounding as necessary.
 1.005 + 17.88 = ?
 56,700 − 324 = ?
 405,007 − 123.3 = ?
 55.5 + 66.66 − 77.777 = ?



Compute and express each answer with the proper number of significant figures, rounding as necessary.
 56.7 × 66.99 = ?
 1.000 ÷ 77 = ?
 1.000 ÷ 77.0 = ?
 6.022 × 1.89 = ?



Compute and express each answer with the proper number of significant figures, rounding as necessary.
 0.000440 × 17.22 = ?
 203,000 ÷ 0.044 = ?
 67 × 85.0 × 0.0028 = ?
 999,999 ÷ 3,310 = ?


 Write the number 87,449 in scientific notation with four significant figures.
 Write the number 0.000066600 in scientific notation with five significant figures.

 Write the number 306,000,000 in scientific notation to the proper number of significant figures.
 Write the number 0.0000558 in scientific notation with two significant figures.


Perform each calculation and limit each answer to three significant figures.
 67,883 × 0.004321 = ?
 (9.67 × 10^{3}) × 0.0055087 = ?


Perform each calculation and limit each answer to four significant figures.
 18,900 × 76.33 ÷ 0.00336 = ?
 0.77604 ÷ 76,003 × 8.888 = ?
Answers
 375 psi
 1.30 cm


 two
 three
 two
 four


 five
 seven
 five
 four


 59.4
 1.011
 13.2
 88.2


 3.80 × 10^{3}
 0.013
 0.0130
 11.4


 8.745 × 10^{4}
 6.6600 × 10^{−5}


 293
 53.3
2.4: Converting Units
 Write the two conversion factors that exist between the two given units.
 milliliters and liters
 microseconds and seconds
 kilometers and meters


Write the two conversion factors that exist between the two given units.
 kilograms and grams
 milliseconds and seconds
 centimeters and meters



Perform the following conversions.
 5.4 km to meters
 0.665 m to millimeters
 0.665 m to kilometers



Perform the following conversions.
 90.6 mL to liters
 0.00066 ML to liters
 750 L to kiloliters



Perform the following conversions.
 17.8 μg to grams
 7.22 × 10^{2} kg to grams
 0.00118 g to nanograms



Perform the following conversions.
 833 ns to seconds
 5.809 s to milliseconds
 2.77 × 10^{6} s to megaseconds



Perform the following conversions.
 9.44 m^{2} to square centimeters
 3.44 × 10^{8} mm^{3} to cubic meters



Perform the following conversions.
 0.00444 cm^{3} to cubic meters
 8.11 × 10^{2} m^{2} to square nanometers


Why would it be inappropriate to convert square centimeters to cubic meters?

Why would it be inappropriate to convert from cubic meters to cubic seconds?


Perform the following conversions.
 45.0 m/min to meters/second
 0.000444 m/s to micrometers/second
 60.0 km/h to kilometers/second



Perform the following conversions.
 3.4 × 10^{2} cm/s to centimeters/minute
 26.6 mm/s to millimeters/hour
 13.7 kg/L to kilograms/milliliters



Perform the following conversions.
 0.674 kL to milliliters
 2.81 × 10^{12} mm to kilometers
 94.5 kg to milligrams



Perform the following conversions.
 6.79 × 10^{−6} kg to micrograms
 1.22 mL to kiloliters
 9.508 × 10^{−9} ks to milliseconds



Perform the following conversions.
 6.77 × 10^{14} ms to kiloseconds
 34,550,000 cm to kilometers



Perform the following conversions.
 4.701 × 10^{15} mL to kiloliters
 8.022 × 10^{−11} ks to microseconds



Perform the following conversions. Note that you will have to convert units in both the numerator and the denominator.
 88 ft/s to miles/hour (Hint: use 5,280 ft = 1 mi.)
 0.00667 km/h to meters/second



Perform the following conversions. Note that you will have to convert units in both the numerator and the denominator.
 3.88 × 10^{2} mm/s to kilometers/hour
 1.004 kg/L to grams/milliliter


What is the area in square millimeters of a rectangle whose sides are 2.44 cm × 6.077 cm? Express the answer to the proper number of significant figures.

What is the volume in cubic centimeters of a cube with sides of 0.774 m? Express the answer to the proper number of significant figures.

The formula for the area of a triangle is 1/2 × base × height. What is the area of a triangle in square centimeters if its base is 1.007 m and its height is 0.665 m? Express the answer to the proper number of significant figures.
The formula for the area of a triangle is 1/2 × base × height. What is the area of a triangle in square meters if its base is 166 mm and its height is 930.0 mm? Express the answer to the proper number of significant figures.
Answers

 \[\frac{1000mL}{1L} and \frac{1L}{1000mL}\]
 \[\frac{1000000\mu s}{1s}and \frac{1s}{1000000\mu s}\]
 \[\frac{1000m}{1km}and \frac{1km}{1000m}\]
 5,400 m
 665 mm
 6.65 × 10^{−4} km


 1.78 × 10^{−5} g
 7.22 × 10^{5} g
 1.18 × 10^{6} ng


 94,400 cm^{2}
 0.344 m^{3}


One is a unit of area, and the other is a unit of volume.


 0.75 m/s
 444 µm/s
 1.666 × 10^{−2} km/s



 674,000 mL
 2.81 × 10^{6} km
 9.45 × 10^{7} mg


 6.77 × 10^{8} ks
 345.5 km


 6.0 × 10^{1} mi/h
 0.00185 m/s


1.48 × 10^{3} mm^{2}


3.35 × 10^{3} cm^{2}
2.5: Other Units  Temperature and Density
 Perform the following conversions.
 255°F to degrees Celsius
 −255°F to degrees Celsius
 50.0°C to degrees Fahrenheit
 −50.0°C to degrees Fahrenheit


Perform the following conversions.
 1,065°C to degrees Fahrenheit
 −222°C to degrees Fahrenheit
 400.0°F to degrees Celsius
 200.0°F to degrees Celsius



Perform the following conversions.
 100.0°C to kelvins
 −100.0°C to kelvins
 100 K to degrees Celsius
 300 K to degrees Celsius



Perform the following conversions.
 1,000.0 K to degrees Celsius
 50.0 K to degrees Celsius
 37.0°C to kelvins
 −37.0°C to kelvins


Convert 0 K to degrees Celsius. What is the significance of the temperature in degrees Celsius?

Convert 0 K to degrees Fahrenheit. What is the significance of the temperature in degrees Fahrenheit?

The hottest temperature ever recorded on the surface of the earth was 136°F in Libya in 1922. What is the temperature in degrees Celsius and in kelvins?

The coldest temperature ever recorded on the surface of the earth was −128.6°F in Vostok, Antarctica, in 1983. What is the temperature in degrees Celsius and in kelvins?

Give at least three possible units for density.

What are the units when density is inverted? Give three examples.

A sample of iron has a volume of 48.2 cm^{3}. What is its mass?

A sample of air has a volume of 1,015 mL. What is its mass?

The volume of hydrogen used by the Hindenburg, the German airship that exploded in New Jersey in 1937, was 2.000 × 10^{8} L. If hydrogen gas has a density of 0.0899 g/L, what mass of hydrogen was used by the airship?

The volume of an Olympicsized swimming pool is 2.50 × 10^{9} cm^{3}. If the pool is filled with alcohol (d = 0.789 g/cm^{3}), what mass of alcohol is in the pool?

A typical engagement ring has 0.77 cm^{3} of gold. What mass of gold is present?

A typical mercury thermometer has 0.039 mL of mercury in it. What mass of mercury is in the thermometer?

What is the volume of 100.0 g of lead if lead has a density of 11.34 g/cm^{3}?

What is the volume of 255.0 g of uranium if uranium has a density of 19.05 g/cm^{3}?

What is the volume in liters of 222 g of neon if neon has a density of 0.900 g/L?

What is the volume in liters of 20.5 g of sulfur hexafluoride if sulfur hexafluoride has a density of 6.164 g/L?
 Which has the greater volume, 100.0 g of iron (d = 7.87 g/cm^{3}) or 75.0 g of gold (d = 19.3 g/cm^{3})?
 Which has the greater volume, 100.0 g of hydrogen gas (d = 0.0000899 g/cm^{3}) or 25.0 g of argon gas (d = 0.00178 g/cm^{3})?
Answers
 124°C
 −159°C
 122°F
 −58°F


 373 K
 173 K
 −173°C
 27°C


−273°C. This is the lowest possible temperature in degrees Celsius.


57.8°C; 331 K


g/mL, g/L, and kg/L (answers will vary)


379 g


1.80 × 10^{7} g


15 g


8.818 cm^{3}


247 L


The 100.0 g of iron has the greater volume
Additional Exercises
 Evaluate 0.00000000552 × 0.0000000006188 and express the answer in scientific notation. You may have to rewrite the original numbers in scientific notation first.

Evaluate 333,999,500,000 ÷ 0.00000000003396 and express the answer in scientific notation. You may need to rewrite the original numbers in scientific notation first.

Express the number 6.022 × 10^{23} in standard notation.

Express the number 6.626 × 10^{−34} in standard notation.

When powers of 10 are multiplied together, the powers are added together. For example, 10^{2} × 10^{3} = 10^{2+3} = 10^{5}. With this in mind, can you evaluate (4.506 × 10^{4}) × (1.003 × 10^{2}) without entering scientific notation into your calculator?

When powers of 10 are divided into each other, the bottom exponent is subtracted from the top exponent. For example, 10^{5}/10^{3} = 10^{5−3} = 10^{2}. With this in mind, can you evaluate (8.552 × 10^{6}) ÷ (3.129 × 10^{3}) without entering scientific notation into your calculator?

Consider the quantity two dozen eggs. Is the number in this quantity "two" or "two dozen"? Justify your choice.

Consider the quantity two dozen eggs. Is the unit in this quantity "eggs" or "dozen eggs"? Justify your choice.

Fill in the blank: 1 km = ______________ μm.

Fill in the blank: 1 Ms = ______________ ns.

Fill in the blank: 1 cL = ______________ ML.

Fill in the blank: 1 mg = ______________ kg.

Express 67.3 km/h in meters/second.

Express 0.00444 m/s in kilometers/hour.

Using the idea that 1.602 km = 1.000 mi, convert a speed of 60.0 mi/h into kilometers/hour.

Using the idea that 1.602 km = 1.000 mi, convert a speed of 60.0 km/h into miles/hour.

Convert 52.09 km/h into meters/second.

Convert 2.155 m/s into kilometers/hour.

Use the formulas for converting degrees Fahrenheit into degrees Celsius to determine the relative size of the Fahrenheit degree over the Celsius degree.

Use the formulas for converting degrees Celsius into kelvins to determine the relative size of the Celsius degree over kelvins.

What is the mass of 12.67 L of mercury?

What is the mass of 0.663 m^{3} of air?

What is the volume of 2.884 kg of gold?

What is the volume of 40.99 kg of cork? Assume a density of 0.22 g/cm^{3}.
Answers
 3.42 × 10^{−18}


602,200,000,000,000,000,000,000


4.520 × 10^{6}


The quantity is two; dozen is the unit.


1,000,000,000


1/100,000,000


18.7 m/s


96.1 km/h


14.47 m/s


One Fahrenheit degree is ninefifths the size of a Celsius degree.


1.72 × 10^{5} g


149 mL