(1) A 10m^3 tank of compressed natural gas has an absolute pressure of 400 kPa at a temperature of 27 C. What is the mass of the gas in the tank? 1 kmole of natural gas weighs 16 kg. R = 8314 J/kmole K.
(2) A 200 meter length of steel rail changes temperature by 30C during the course of a day. If the coeffcient of thermal expansion of steel is 12 parts per million per C, what is the change in length of the steel?