Question

An earthquake generates what transverse (S) and longitudinal (P) sound waves in the earth the speed of S waves is about 4.5 km/s and that of p waves is about 8 km/s. A seismograph records P and S waves from an earthquake the. first P wave arrives 4 minutes before the first S wave. the epicenter of earthquake is located at a distance about?
1 ) 25km
2) 250km
3) 2500km
4) 5000km

Answer 1

Ans: (3) 2500 km

Explanation:

Let the epicenter of the earthquake be at a distance of x from the origin (focus) of the earthquake.

Therefore, difference between the time taken by the P waves and S waves to reach the focus are 4 minutes = 240 seconds.

Therefore, (x/4.5) – (x/8) = 240

Therefore, x = 2470 km = 2500 km

Hope it helps:)