# Homework Help: Distance To Center of Earthquake?

1. Dec 23, 2007

### mrlucky0

[SOLVED] Distance To Center of Earthquake?

1. The problem statement, all variables and given/known data

An earthquake releases two types of traveling waves, called "traverse" and "longitudinal." The average speed of traverse and longitudinal seismic waves in rock are 8.9 km/s and 5.1 km/s respectively. A seismograph records the arrival of the traverse waves 73 s before that of the longitudinal waves. Assuming that the waves travel in straight lines, how far away is the center of the earthquake from the seismograph?

2. Relevant equations

3. The attempt at a solution

I only know that (73 s * 5.1 km/s) gives me part of the distance from the seismograph to the earthquake.

2. Dec 23, 2007

### Shooting Star

It's "transverse".

Suppose the epicentre is x km away.

For the transverse waves, x = (8.9)t.
For the longitudinal waves, x = (5.1)(t + 73).

Find x now.

3. Dec 23, 2007

### mrlucky0

Thank you. I wasn't thinking it had to be a system of equations.