Warm­Up
3) SAT question:
If
Simplify:
1) 811/4
A.
B.
C.
D.
2) (196a6b­2c)1/2
E.
and
what is the value of m?
Richter Scale
The Richter magnitude scale, also known as the local magnitude (ML) scale, assigns a single number to quantify the amount of seismic energy released by an earthquake. It is a base­10 logarithmic scale obtained by calculating the logarithm of the combined horizontal amplitude (shaking amplitude) of the largest displacement from zero on a particular type of seismometer (Wood–
Anderson torsion). So, for example, an earthquake that measures 5.0 on the Richter scale has a shaking amplitude 10 times larger than one that measures 4.0. The effective limit of measurement for local magnitude ML is about 6.8.
April 29, 2003
Just before 5 a.m. a moderate earthquake, rated 4.9 on the Richter Scale, shook most of the northwest corner of Georgia, south to Atlanta. The epicenter was located in Menlo, Georgia, about 37 miles south of Chattanooga.
Other bases:
What if we want to solve problems when the base is not 10?
1) 2x = 32
2) 5x = 125
3) 73x ­ 13 = 49
Logarithms of base b: What exponent of b gives this number?
log2 (16) is what exponent of 2 gives 16?
logb (x) is what exponent of b gives x?