A plane is in level fight at constant speed and each of its two wings has an area of 25 m2. If the speed of the air on the upper and lower surfaces of the wing are 270 kmph and 234 kmph respectively,then mass of the plane is (take the density of air is 1 kgm3

Let v1, v2 are the speed of air on the lower and upper surface S of the wings of the plane P1 and P2 are the Pressure there.According to Bernoulli's theoremP1+12ρv12 = P2+12ρv22P1-P2 = 12ρ(v22-v12)Here, v1 = 234 km h-1 = 234×518ms-1 = 65 ms-1 v2 = 270 km h-1 = 270×518 = 75 ms-1Area of wings = 2× 25 m2 = 50 m2P1-P2 =12×1(752-652)Upward force on the plane = (P1-P2)A = 12×1×(752-652)×50 mAs the plane is in level flight, therefore upward force balances the weight of the planemg = (P1-P2)AMass of the plane,m = (P1-P2)gA  = 12×1×(752-652)10×50= (75+65)(75-65)×502×10 = 3500 kg