A 400-ft equal tangent sag vertical curve has its PVC at station 100 00 and elevation 500 ft. The initial grade is -4.0% and the final frade is 2.5%. Determine the elevation of the lowest point of the curve.

10 kg of co2 is initially contained at 400 kpa and 300 k. the gas constant for carbon dioxide is 189 j/lkg k) and has a specific heat ratio, k, of 1.289. isentropic expansion then occurs until the pressure is 200 kpa. a) determine the initial volume of co2 in m. b) determine the final temperature in k. c) determine the work done by the system during the expansion kl.