A plane is in level flight at a constant speed such that the speed of the air below the wings is 144 km h - 1 and above the wing is 180 km h - 1 . If each of its wings has an area of 25 m 2 , then the mass (in kg ) of the plane is [ ρ air = 1 kg m - 3 , g = 10 m s - 2 ]

Step-by-step solution

Given, A = 25   m 2 [area of each wing] v 1 = 180 × 5 18   m   s - 1 = 50 m s - 1 [speed of the air above the wing] v 2 = 144 × 5 18   m   s - 1 = 4 0  m   s - 1 [speed of the air below the wing] According to Bernoulli's theorem P 1 + 1 2 ρ air v 1 2 = P 2 + 1 2 ρv 2 2 ⇒P 2 - P 1 = 1 2 ρ air v 1 2 - v 2 2 ⇒ P 1 - P 2 = 1 2 × 1 × 50 2 - 40 2 ⇒ ∆ P = 450   Pa The lifting force acting on the plane is ∆ P &