Exponential and Logarithmic Functions

Applications of Logarithms

See below for videos and images explaining three common applications of the logarithm.

Assignment

• Textbook 8-3: 1-5 (Richter Scale)
• Textbook 8-3: 26-34, 49 (pH Scale)
• Textbook 8-3: 85-89 (Sound Intensity, db)
• Textbook 8-4: 31-32, 56, 70 (Sound Intensity, db)

Resources

• Solutions with steps shown, by Staublin
• 8-3 Answer Key
• 8-4 Answer Key
• On-line tutor: phschool.com, age-0803 or -0804
• On-line practice quiz: phschool.com, aga-0803 or -0804
• Solutions with steps shown at slader.com

Richter Scale

A 1-point change in Richter scale corresponds to a 10-times increase in displacement.

Acidity (pH)

A 1-point change in pH indicates a 10-times change in concentration of hydrogen ion [H⁺].

Sound Intensity (db)

A 10-point change in db is perceived by humans as a doubling of volume, but is a 10-times change in sound intensity.