12. A seismologist positions two recording devices 340 feet apart at points A and B. To check the calibration, an explosive is detonated between the devices 90 feet from point A. The time the
explosions register on the devices is noted and the difference calculated. A second explosion will
be detonated cast of point A. How far cast should the second explosion be positioned so that the
measured time difference is the same as for the first explosion? (Hint: 1 mile - 5280ft, sound
travels at approximately 1100 ft/sec)