[B] Earthquakes generate two sorts of waves in rock, shear or 5 waves which travel at about 4.5 km/s and pressure or P waves traveling at about 8 km/s. (1) After one such quake, a seismograph station picks up the S wave 3.0 minutes after the P wave. How far away was the source, or epicenter, of the earthquake? | (2) When a quake is detected, a steady 250 Hz alarm sounds in the hallway of a facility to alert the person on watch. The alarm is also sent to the cell phones of the staff on duty which emit the same 250 Hz tone. One of the staff responding to the alert runs down the hall, approaching the hallway speaker. She notices a 2 Hz variation in the loudness of the 250 Hz tone as she runs with her phone. What frequency is she hearing from the speaker? From your answer, how fast was she running, if the speed of sound is 344 m/s? A wave traveling through granite comes to a boundary with sandstone. The effective bulk modulus and density for each of these rocks is given in the table below.…

(II) Two earthquake waves of the same frequency travelthrough the same portion of the Earth, but one is carrying5.0 times the energy. What is the ratio of the amplitudesof the two waves?

(II) P and S waves from an earthquake travel at different speeds, and this difference helps locate the earthquake “epicenter” (where the disturbance took place). (a) Assuming typical speeds of 8.5 km/s and 55 km/s for P and Swaves, respectively, how far away did an earthquake occur if a particular seismic station detects the arrival of these two types of waves 1.5 min apart? (b) Is one seismic station sufficient to determine the position of the epicenter? Explain.

A person observes a wave (swell) originating at a certain distance from the beach where it is located. Not the time to, because the waves had period T = 8s and %3D that, not the time t1 = to + 2.4×10°s, now has a period of T = 6s. Ask: (1) The distance between the beach and the point where the swell was started.

Waves in a lake are spaced 5.00 m and pass an anchored boat 1.25 sec apart. (a) How long before a particular wave crest can return to pass underneath a boat a hundred meters away from the shoreline? (b) if we will stay longer to see the boat tossed up and down a hundred times, how long will we have to wait?

(II) A bug on the surface of a pond is observed to moveup and down a total vertical distance of 7.0 cm, from thelowest to the highest point, as a wave passes. If the ripplesdecrease to 4.5 cm, by what factor does the bug’s maximumKE change?

(III) A longitudinal earthquake wave strikes a boundary between two types of rock at a 38° angle. As the wave crosses the boundary, the specific gravity changes from 3.6 to 2.5. Assuming that the elastic modulus is the same forboth types of rock, determine the angle of refraction.

An earthquake on the ocean floor in the Gulf of Alaska produces a tsunami (sometimes incorrectly called a "tidal wave") that reaches Hilo, Hawaii, 5,420 km away, in a time interval of 8 h 30 min. Tsunamis have enormous wavelengths (100 to 200 km). From the information given, find the average ocean depth between Alaska and Hawaii. (This method was used in 1856 to estimate the average depth of the Pacific Ocean long before soundings were made to give a direct determination.) Propagation speed of the wave, v≈sqrt(gd); where d is the average ocean depth. Use g=9.8m/s .State your answer to the nearest meter.

(i) In a long line of people waiting to buy tickets, the first person leaves and a pulse of motion occurs as people step forward to fill the gap. As each person steps forward, the gap moves through the line. Is the propagation of this gap (a) transverse or (b) longitudinal? (ii) Consider “the wave” at a baseball game: people stand up and raise their arms as the pulse arrives at their location, and the resultant pulse moves around the stadium. Is this pulse (a) transverse or (b) longitudinal?