Physics Waves And Oscillations Level: Misc Level

Earthquakes produce two kinds of seismic waves; The longitudinal primary waves(called p waves) and transverse secondary waves(called s waves).Both s waves and p waves travel through Earth,s crust and mantle, but at different speeds; the p waves are faster than s waves, but their exact speeds depend on depth and location.Assume the p waves speed to be vp=8580 m/s while the s waves travel at a slower speed of vs=5570 m/s. suppose a seismic station detects a wave and then ^t=93.5 s later detects an s wave.How far away is the earthquake center?Answer in units of km.