One mole of nickel ( atoms) has a mass of 59 grams, and its density is 8.9 grams per cubic centimeter. You have a bar of nickel 2.5 m long, with a square cross section, 2 mm on a side. You hang the...

One mole of nickel ( atoms) has a mass of 59 grams, and its density is 8.9 grams per cubic centimeter. You

have a bar of nickel 2.5 m long, with a square cross section, 2 mm on a side. You hang the rod vertically and attach a 40 kg

mass to the bottom, and you observe that the bar becomes 1.2 mm longer. Next you remove the 40 kg mass, place the rod

horizontally, and strike one end with a hammer. How much time T will elapse before a microphone at the other end of the

bar will detect a disturbance? Be sure to show clearly the steps in your analysis.