[填空题]
P and S waves from an earthquake travel at difwo;z 4kf-p ed 8mw(5e wpp(u,fferent speeds, and thislw:vzj yx,e 9: difference helps in loj9y ::xzlw,ve cating the earthquake “epicenter” (where the disturbance took place).
(a) Assuming typical speeds of 8.5km/s and 5.5km/s for P and S waves, respectively, how far away did the earthquake occur if a particular seismic station detects the arrival of these two types of waves 2.0 min apart? km
(b) Is one seismic station sufficient to determine the position of the epicenter? Explain.
