2. A 500-cell PEM fuel cell stack for fuel cell vehicles is assembled from 500 membrane electrode assemblies (MEAs) interspersed between 501 bipolar plates. Each MEA consisting of 5 layers (2 gas diffusion layers, two catalyst layers, and the PEM membrane) is 500 um thick. Each bipolar plate is 1 mm thick. The fuel cell stack is delivering its maximum current density of 1 A/cm at an average cell voltage of 0.6 V. What is the stack voltage (V)? If the stack is 300 cm? in area, what is the output current? What is the output power? What is the stack volume? ( Determine thickness of 500 MEAs and 501 bipolar plates and multiply by stack area.) What is the power density (W/L)? If the stack has a density of 1.5 kg/L, what is the specific power (W/kg)? If the platinum loading is 0.5 mg/cm for each 300 cm MEA, how much platinum is in the 500 MEAs in the fuel cell stack. Assuming the platinum metal cost is $30/g, what is the cost of the platinum in the fuel cell? How does this compare to the DOE fuel cell system cost target of $25/kW