Earthquakes are essentially sound waves travelling through the earth. They are called seismic waves. Because the earth is solid, it can support both longitudinal and transverse seismic waves, which travel at different speeds. The speed of longitudinal waves, called P waves, is 8240.0m/s. Transverse waves, called S waves, travel at a slower 4179.0m/s. A seismograph records the two waves from a distant earthquake. If the S wave arrives 2.83min after the P wave, how far away was the earthquake? You can assume that the waves travel in straight lines, although actual seismic waves follow more complex routes.