Exponential Functions

Question

An earthquake of 6.7 occurred off the coast of British Columbia. A few hours later an aftershock occurred that was 150 times less intense than the original earthquake. What was the magnitude of the aftershock?

Answer 1

The scale of an earthquake is a logarithmic scale, also known as the Richter scale. I believe (I'm not an Earth Science pro, but the title and wikipedia agree on the scaling.)

The question states that the magnitude is 150 times less and wants to know the magnitude. The equation we need to write is thus:

magnitude = 6.7 - log 150.

The equation is 6.7 - log 150 because the magnitude is less. It would be 1/150 th of the magnitude, and for a logarithmic scale you can simple translate that to the negative log of the value. Given all of these tips the answer should be solvable, though any questions can be sent my way.