Logarithmic Functions Apply, Unit 6: Lesson 2 help

1. OPEN ENDED Give an example of an exponential equation and its related logarithmic equation.

Writing in Math Use the information about sound on page 529 to explain how a logarithmic scale can be used to measure sound. Include the relative intensities of a pin drop, a whisper, normal conversation, kitchen noise, and a jet engine written in scientific notation. Also include a plot of each of these relative intensities on the scale below and an explanation as to why the logarithmic scale might be preferred over the scale below.

GET READY for the Lesson
Many scientific measurements have such an enormous range of
possible values that it makes sense to write them as powers of 10 and
simply keep track of their exponents. For example, the loudness of
sound is measured in units called decibels. The graph shows the
relative intensities and decibel measures of common sounds.
Sound
10
10
10
10
Relative
Intensity
Decibels
+++
10 10 10
+++
20 40 60
whisper
normal
(4 feet)
conversation
80
0
pin
120
100
noisy
kitchen
drop
jet engine
The decibel measure of the loudness of a sound is the exponent or
logarithm of its relative intensity multiplied by 10.