1.4 Measurements

Question 1

Units

Answer 1

Standard of comparison for measurements.

Question 2

SI units (International System of Units)

Answer 2

Standard fixed by international agreement in the International System of Units.

Question 3

Length

Answer 3

Measure of one dimension of an object.

Question 4

Meter (m)

Answer 4

Standard metric and SI unit of length; 1 m = approximately 1.094 yards.

Question 5

Kilogram (kg)

Answer 5

Standard SI unit of mass; 1 kg = approximately 2.2 pounds.

Question 6

Kelvin (K)

Answer 6

SI unit of temperature; 273.15 = 0 degrees Celsius.

Question 7

Celsius

Answer 7

Unit of temperature; water freezes at 0 degrees Celsius and boils at 100 degrees Celsius on this scale.

Question 8

Second (s)

Answer 8

SI unit of time

Question 9

Cubic meter (m^3)

Answer 9

SI unit of volume

Question 10

Liter (L)

Answer 10

(also, cubic decimeter) unit of volume, 1 L = 1,000 cm^3

Question 11

Cubic Centimeter (cm^3 or cc)

Answer 11

Volume of a cube with an edge length of exactly 1 cm.

Question 12

Milliliter (mL)

Answer 12

1/1,000 of a liter; equal to 1 cm^3

Question 13

Density

Answer 13

ratio of mass to volume for a substance or object.

Question 14

Lead is a dense substance, but its density is not as great as that of gold, 19.3 g/cm^3. What is the density of lead if a cube of lead has an edge length of 2.00 cm and a mass of 90.7 g?

Answer 14

volume of lead cube = 2.00 cm x 2.00 cm x 2.00 cm = 8.00 cm^3

density = mass/volume = 90.7 g/8.00 cm^3 = 11.3 g/cm^3

Question 15

(a) To three decimal places, what is the volume of a cube (cm^3) with an edge length of 0.843 cm?
(b) If the cube in part (a) is copper and has a mass of 5.34 g, what is the density of copper to two decimal places?

Answer 15

(a) 0.599 cm^3; (b) 8.91 g/cm^3

Question 16

Is one liter about an ounce, a pint, a quart, or a gallon?

Answer 16

A Quart

Question 17

Is a meter about an inch, a foot, a yard, or a mile?

Answer 17

About a yard

Question 18

Indicate the SI base units or derived units that are appropriate for the following measurements:
(a) the length of a marathon race (26 miles 385 yards)
(b) the mass of an automobile
(c) the volume of a swimming pool
(d) the speed of an airplane
(e) the density of gold
(f) the area of a football field
(g) the maximum temperature at the South Pole on April 1, 1913

Answer 18

(a) The length of a marathon race (26 miles; 385 yards): The appropriate Si unit is the meter (m). A marathon is approximately 42,195 meters.
(b) The mass of an automobile: The appropriate SI unit is the kilogram (kg).
(c) The volume of a swimming pool: The appropriate SI unit is the cubic meter (m^3).
(d) The speed of an airplane: The appropriate SI unit is meters per second (m/s)
(e) The density of gold: The appropriate SI unit is kilograms per cubic meter (kg/m^3).
(f) The area of a football field: The appropriate SI unit is the square meter (m^2)
(g) The maximum temperature at the South Pole on April 1, 1913: The appropriate SI unit is the kelvin (K), though degrees Celsius (°C) is also commonly used.

Question 19

Indicate the SI base units or derived units that are appropriate for the following measurements:
(a) the mass of the moon
(b) the distance from Dallas to Oklahoma City
(c) the speed of sound
(d) the density of air
(e) the temperature at which alcohol boils
(f) the area of the state of Delaware.
(g) the volume of a flu shot or a measles vaccination.

Answer 19

(a) kilograms; (b) meters; (c) kilometers/second; (d) kilograms/cubic meter; (e) kelvin; (f) square meters; (g) cubic meters

Question 20

Give the name and symbol of the prefixes used with SI units to indicate multiplication by the following exact quantities.
(a) 10^3
(b) 10^-2
(c) 0.1
(d) 10^-3
(e) 1,000,000
(f) 0.000001

Answer 20

(a) 10³: kilo (k), (b) 10⁻²: Centi, (c) 0.1: Deci (d) 10⁻³: milli (m) (e) 1,000,000: mega (M) (f) 0.000001: micro (µ)

Question 21

Give the name of the prefix and the quantity indicated by the following symbols that are used with SI base units.
(a) c
(b) d
(c) G
(d) k
(e) m
(f) n
(g) p
(h) T

Answer 21

(a) Centi, x 10^-2
(b) Deci, x 10^-1
(c) Giga x 10^9
(d) Kilo x 10^3
(e) Milli x 10^-3
(f) Nano x 10^-9
(g) Pico x 10^-12
(h) Tera x 10^12

Question 22

A large piece of jewelry has a mass of 132.6 g. A graduated cylinder initially contains 48.6 mL water. When the jewelry is submerged in the graduated cylinder, the total volume increases to 61.2 mL.
(a) Determine the density of this piece of jewelry.
(b) Assuming that the jewelry is made from only one substance, what substance is it likely to be? Explain.

Answer 22

(a) Determine the density of the jewelry
- Calculate the volume of the jewelry:
– Initial volume of water: 48.6 mL
– Final volume of water (with jewelry): 61.2 mL
– Volume of the jewelry = Final volume - Initial volume
– Volume of the jewelry = 61.2 mL - 48.6 mL = 12.6 mL

• Calculate the density:
  – Density = Mass/Volume
  – Mass of the jewelry = 132.6 g
  – Volume of the jewelry = 12.6 mL
  – Density = 132.6 g/ 12.6 mL = 10.52 g/mL

(b) Identify the likely substance
- To identify the substance, we compare the calculated density with known densities of various materials. The density of the jewelry is approximately 10.52 g/mL.
- Gold: 19.32 g/m:
- Platinum: 21.45 g/m:
- Lead: 11.34 g/mL
- Copper: 8.96 g/mL
Given the density of 10.52 g/mL, the jewelry is likely to be made of lead.