Consider a pemfc operating at 0.8 a/cm2 and 70∘c. hydrogen gas at 90∘c and 80% relative humidity is provided to the fuel cell at the rate of 8 a. the fuel cell area is 8 cm2 and the drag ratio of water molecules to hydrogen, α, is 0.8. find the water activity of the hydrogen exhaust. assume that p = 1atm and that the hydrogen exhaust exits at the fuel cell temperature, 70∘c.

Study the diagram showing the range of temperature in the earth’s layers. which temperature most likely corresponds to the asthenosphere? 1,613°c 2,521°c 3,628°c 6,217°c

11. you want to calculate the displacement of an object thrown over a bridge. using -10 m/s2 for acceleration due to gravity, what would be the total displacement of the object if it took 8 seconds before hitting the water?

Four objects each with charge +2.0×10−7c are located at the corners of a square whose sides are 2.0 m long. part a what quantities can be determined using this information? check all that apply. the electric force on a charged object placed at the center of the square. the mass of each object. the total electric potential energy of the system consisting of the four charged objects. part b find the electric force on a charged object placed at the center of the square.