When a compressed gas storage tank fails, the resultant explosion occurs so rapidly that the gas cloud can be considered adiabatic and assumed to not mix appreciably with the surrounding atmosphere. Consider the failure of a 2.5 m^3 air storage tank initially at 15 bar. Atmospheric pressure is 1 bar, C_p=7R/2. Provide an estimate by assuming reversibility.
a) Calculate the work done on the atmosphere. Does the reversibility approximation over-estimate or under-estimate the actual work?
b) A detonation of 1 kg of TNT releases about 4.5 MJ of work. Calculate the equivilent mass of TNT that performs the same work as in part (a).