Question

2. The formula determines the magnitude of an earthquake, where I is the intensity of the earthquake and S is the intensity of a “standard earthquake.” How many times stronger is an earthquake with a magnitude of 8 than an earthquake with a magnitude of 6? Show your work.

Answer 1

M=log I / S
if M=6, 6=logI/S and then 10^6=I/S, so we get I=S x 10^6, we assume that 
A=S x 10^6
if M=8, so, 8=logI/S and then 10^8=I/S, so we get I= S x 10^8=A=S x 10^6x10^2 
since A=S x 10^6, so I= A x10^2, an earthquake with a magnitude of 8 is 10² stronger than an earthquake with a magnitude of 6.