on a vacation flight, you look out the window of the jet and wonder about the fo

Question

on a vacation flight, you look out the window of the jet and wonder about the forces exerted on the window. Suppose the air outside the window moves with a speed of approximately 170 m/s shortly after takeoff, that the air inside the plane is at atmospheric pressure and that the density of the air inside and outside the plane is 1.29 kg/m (a)Find the pressure difference between the inside and outside of the window -kPa (b)If the window is 25 cm by 39 cm, find the force exerted on the window by air pressure-kN I have no idea how to do this question can you please help me-Ive tried everything
on a vacation flight, you look out the window of the jet and wonder about the forces exerted on the window. Suppose the air outside the window moves with a speed of approximately 170 m/s shortly after takeoff, that the air inside the plane is at atmospheric pressure and that the density of the air inside and outside the plane is 1.29 kg/m (a)Find the pressure difference between the inside and outside of the window -kPa (b)If the window is 25 cm by 39 cm, find the force exerted on the window by air pressure-kN I have no idea how to do this question can you please help me-Ive tried everything

Explanation / Answer

(a)The air outside the window moves with a speed of v = 170 m/s The air inside the plane is at pressure P = 1 atm = 1.013 * 105 Pa = 101.3 * 103 Pa = 101.3 kPa The density of the air inside and outside the plane is ? = 1.29 kg/m^3 According to Bernoulli's equation,we have P + ?gh + (1/2)?v^2 = P1 + ?gh1 + (1/2)?v1^2 Here,h = h1 or P + (1/2)?v^2 = P1 + (1/2)?v1^2 ----------(1) According to equation of continuity,we have Av = constant or A * v = A1 * v1 or v1 = (A * v/A1) -----------(2) where A1 = 25 cm * 39 cm = 25 * 39 * 10^-4 m^2 We know from the relation P = F * v or F = (P/v) We know that P = (F/A) or A = (F/P) -----------(3) From equations (2) and (3),we get v1 = ((F/P) * v/A1) -----------(4) From equation (1),we get P1 - P = (1/2)? * (v^2 - V1^2) Substituting the value of v1 from equation (4) in the above equation we get the pressure difference. (b)The force exerted by air on the window is P1 - P = (F/A) or F = (P1 - P) * A

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