Exponential and Logarithmic Functions
Exponential Functions are used to model growth of populations, interest on an investment, depreciation of cars, decay of radioactivity, and many other real-life things. Logarithmic Functions are used to measure earthquakes (Richter Scale), Acidity (pH), and Sound Intensity (decibels).
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.
