Physics-
General
Easy
Question
Earthquakes generate sound waves inside Earth. Unlike a gas, Earth can experience both transverse (S) and longitudinal (P) sound waves. Typically, the speed of S waves is about 4 km/s. A seismograph records P and S waves from an earthquake. The first P waves arrive 3.0 min before the first S wave (figure). Assuming the waves travel in a straight line, how far away does the earthquake occur ? (Yearth = 12.8 
1010 pa, rearth = 2000 kg/m3 )
- 1900 km
- 1440 km
- 1800 km
- 1200 km
The correct answer is: 1440 km
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