The arrival rate at a parking lot is 6 veh. min. Vehicles start arriving at 6:00PM and when the queue reaches 36 vehicles, service begins. If company policy is that total vehicle delay should be equal to 500 veh-min, what is the departure rate?

Ahe-xe mixture containing a 0.75 mole fraction of helium is used for cooling electronics in an avionics application. at a temperature of 300 k and atmospheric pressure, calculate the mass fraction of helium and the mass density, molar concentration and molecular weight of the mixture. if the cooling capacity is 10 l, what is the mass of the coolant?