A balloon of diameter 20 m weighs 100 Kg. Calculate its payload if it is filled with helium at 1.0 atm and 27∘C. Density of air is 1.2 Kg m−3(R=0.082 dm3 atm K−1 mole−1)
4247 Kg
Volume of balloon = 43πr3=43×227×103=4190.47 m3
Mass of the air displaced = 4190.47×1.2 = 5028.56 Kg
No of moles of helium in the balloon=(PV/RT)
=1×4190.47×1030.082×300
=170344
Mass of helium = 4×170.344×103 = 681.376 Kg
Mass of filled balloon = 681.376+100 =781.376 Kg
Pay load = Mass of air displaced - Mass of filled balloon
=5028.56-781.376
=4247.184 Kg