Question

A seismographic station receives S and P waves from an earthquake, separated in time by 17.8 s. Assume the waves have traveled over the same path at speeds of 4.50 km/s and 6.90 km/s. Find the distance from the seismograph to the focus of the quake.

Answer 1

Answer:

D = 230.2 Km

Explanation:

let distance between seismograph and focus of quake is D

From time distance formula we  can calculate the time taken by the S wave

$T_1 =\frac{D}{4.5}$

From time distance formula we  can calculate the time taken by the P wave

$T_2 =\frac{D}{6.90}$

It is given in equation both waves are seperated from each other by 17.8 sec

so we have

$T_1 - T_2 = 17.8$sec

Putting both time value to get distance value

$\frac{D}{4.5} - \frac{D}{6.90} = 17.8$

D = 230.2 Km