CBSE Class 11-science Answered

Volume of balloon = 4/3 ¶r³ = 4/3 x 22/7 x 10³ = 4190.5 m³ = 4190.5 x 10³ dm³

Mass of He filled in the balloon :

                                        PV=nRT

                                   PV = m/M x R XT

         1.66 X 4190.5 X 10³x 4

m=----------------------------- = 1117.47g = 1117.47 kg

       0.083 X300

Total mass of balloon =100 +1117.47

                                       =1217.47 kg

Volume of air displaced by ballon =4190.5m³

Mass of displaced air = volume X density

                                       =4190.5 X 1.2 = 5028.6 kg

  Payload= 5028.6-1217.47

             = 3811.1 kg

m = --------------------------