PHYS 2211 Module 1.3

Unit Conversion

Recommended Reading

1.3 Unit Conversion

Learning Objectives

By the end of this section, you will be able to:

  • Use conversion factors to express the value of a given quantity in different units.

A conversion factor is a ratio that expresses how many of one unit are equal to another unit.

Practice!

Practice 1.3.1
Select the correct conversion factors that indicate the number of centimeters (cm) in one inch (in).
(a) or
(b) or
(c) or
(d) or
Practice 1.3.2
Calculate the number of inches (in) in 2.85 meters (m).  
(a) 0.0723 inches
(b) 39.4 inches
(c) 2.85 inches
(d) 112 inches
Practice 1.3.3
Select the correct conversion factors that indicate the number of grams (g) in one pound (lb).
(a) or
(b) or
(c) or
(d) or
Practice 1.3.4
Calculate the number of kilograms (kg) in 15.8 pounds (lb). 
(a) 34.8 kilograms
(b) 7.18 kilograms
(c) 2.20 kilograms
(d) 15.8 kilograms
Practice 1.3.5
One meter is 100 cm.  If you have a hot tub with a volume of 1 cubic meter (1 m3), how many cubic centimeters is that?
(a) 100 cm3
(b) One thousand cm3
(c) One million cm3
(d) One billion cm3
Practice 1.3.6
Lead has a density of 11.3 g/cm3. If you have 1.0 kg of lead, what is the volume in cubic centimeters (cm3)?
(a) 11.3 cm3
(b) 0.0885 cm3
(c) 88.5 cm3
(d) 88 cm3

Discuss!

Consider how you would answer this question. Then bring this to class for a group discussion.

You need to get to the airport. Would you rather drive 55 mph or 35 m/s? Why?