speed of sound

eriments in Introductory Physics Home or Lab 1. If the speed of light is assumed to be 3 x 108 m/sec, calculate the approximate distance to the lightning flash if the thunder is heard 10 seconds after the flash and the temperature is 25.C 2. Disturbances generated by earthquakes can generate both longitudinal, that is, compressive waves like soundwaves and transverse or shear waves. The designation of the compressional wave is a 'p wave' (for primary) and the shear wave as 'S wave.' Their velocity varies directly as the resistance of the solid to compression and inversely to its density. The P and S waves do not travel with the same speed. Their time lag, as recorded with a seismograph permits the calculation to the epicenter, the point on the Earth's surface above the earthquake. Assume that the P wave travels at a speed of 2000 m/sec and the S wave at a speed of 1500 m/sec. The time delay between the P and the S wave, as recorded by a seismograph station, is 15 minutes. Calculate the distance to the epicenter, a) in kilometers, b) in miles. 3. A well driller wants to check the depth of his well. He drops a pebble down the pipe and hears the splash after 10 seconds. Calculate the depth. You may assume that g = 10 m/sec2. and that the sound has a speed of 340 m/sec. (Hint: equate /2 gti with vt2, where to is the time of fall of the stone and to is the time for the returning sound.)