You have just taken up a job in the R&D office of Fuel-n-Fun, a company that specializes in fossil-fuel-based children's products. Your first assignment is to evaluate three proposals for the design of a gasoline-powered device to entertain babies. Each design is based around air (use C,= 5/2R) in a cylinder with a piston that moves up and down in response to heating/cooling. All added heat for the various processes comes from burning gasoline (35MJ/L). The thermodynamic cycles associated with the three designs (for a fixed baby-weight) can be modelled by the following PV diagrams, where in all cases, the temperature at the bottom-left corner of the cycle is 300K. Pa) isothermal P() padinbatic 200 120 120 120 IOL 30L JOL 30L lo L 30L Psychologists have determined the happiness of a baby on such a device is directly proportional to the net work performed on them per time (up to a limit), regardless of the design. If we want to produce a certain amount of net work by burning the least amount of fuel, which is the most efficient design, and what is its efficiency? For this design, how much gasoline do we have to burn per hour if we want the baby to move up and down 10 times per minute?