Earthquakes produce several types of shock waves. The best knownare the P-waves (P for primary or pressure) and the S-waves (S forsecondary or shear). In the earth's crust, P-waves travel at around6.40 {\rm km}/{\rm s} while S-waves move at about 3.50 {\rmkm}/{\rm s}. (The actual speeds vary with the type of material thewaves are going through.) The time delay between the arrival ofthese two types of waves at a seismic recording station tellsgeologists how far away the earthquake that produced the wavesoccurred.
f the time delay at a seismic station is 38.0 {\rm s}, how far fromthat station did the earthquake occur?
One form of earthquake warning system detects the faster (but lessdamaging) P-waves and sounds an alarm when they first arrive,giving people a short time to seek cover before the more dangerousS-waves arrive. If an earthquake occurs 373 {\rm km} away from sucha warning device, how much time would people have to take coverbetween the alarm and the arrival of the S-waves?
Earthquakes produce several types of shock waves. The best knownare the P-waves (P for primary or pressure) and the S-waves (S forsecondary or shear). In the earth's crust, P-waves travel at around6.40 {\rm km}/{\rm s} while S-waves move at about 3.50 {\rmkm}/{\rm s}. (The actual speeds vary with the type of material thewaves are going through.) The time delay between the arrival ofthese two types of waves at a seismic recording station tellsgeologists how far away the earthquake that produced the wavesoccurred.
f the time delay at a seismic station is 38.0 {\rm s}, how far fromthat station did the earthquake occur?
One form of earthquake warning system detects the faster (but lessdamaging) P-waves and sounds an alarm when they first arrive,giving people a short time to seek cover before the more dangerousS-waves arrive. If an earthquake occurs 373 {\rm km} away from sucha warning device, how much time would people have to take coverbetween the alarm and the arrival of the S-waves?
