[填空题]
P and S waves from an earthquake travel at different sp ccb1x 9)/utwyeeds, and this d )o(d e4ca*nzn2/qov v0iod+bifference helps in locating the earthquake “epicenter” (where the disturbance took place).)no*d4cen dq+ o/(vo bz iv2a0 (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.