When an earthquake occurs, two types of sound waves are generated and travel through the earth. The primary, o?
When an earthquake occurs, two types of sound waves are generated and travel through the earth. The primary, or P, wave has a speed of about 10.5 km/s and the secondary, or S, wave has a speed of about 5.5 km/s. A seismograph, located some distance away, records the arrival of the P wave and then, 140 s later, records the arrival of the S wave. Assuming that the waves travel in a straight line, how far is the seismograph from the earthquake?