Methane (ch4) at 25c, 1 atm enters a furnace operating at steady state and burns completely with 140% of theoretical air entering at 400 k, 1 atm. the products of combustion exit at 700 k, 1 atm. kinetic and potential energy effects are negligible. if the rate of heat transfer from the furnace to the surroundings is 400 kw, determine the mass flow rate of methane, in kg/s.

Why is rain likely when warm, moisture-laden air meets cold air? a) the lighter warm air will rise and cool down, causing condensation and rain. b) the cold air moves faster and pushes the warm air away, causing condensation and rain. c) the moisture in the warm air condenses on contact with the cold air, causing rain to fall. d) the cold air mixes with the warm air, reducing its temperature causing moisture to condense.