I have been given/ have figured out:
the boyant force, the mass of the air in the balloon, the mass of the load, the volume of the balloon, the temperature of the surrounding air, the atmospheric pressure, the density of the air, and air molar mass.
but i dont know how to find what the air temperature must be to lift the balloon and load. Help?? her's the question:
A hot air balloon stays aloft because hot air at atmospheric pressure is less dense than cooler air at the same pressure. If the volume of the balloon is 500m^3 and the surrounding iar is at 15 degrees C, what must the temperature of the air in the balloon be for it to lift the total load of 290 kg(in addition to the mass of the hot air)? The density of air at 15 degrees C and atmpospheric pressure 1.013 x 10^5 Pa is 1.23Kg/m^3. Air molar mass is 29g/mol. Present your answer in Fahrenheits rounded to the whole number.
2007-12-15 15:15:45 · 1 answers · asked by Anonymous in Science & Mathematics ➔ Engineering
If the air in the balloon were 15 degrees C it would weigh 500m^3 X 1.23Kg/m^3 = 615Kg. You need 290Kg of lift so you need the balloon to contain 615Kg - 290Kg = 325Kg of air.
325Kg / 500m^3 = 0.65Kg/m^3 So you need to find the temperature that will give you a density of 0.65Kg/m^3.
2007-12-15 17:14:36 · answer #1 · answered by Tim C 7 · 0⤊ 0⤋