NEET2013PhysicsMechanical Properties of FluidsActual
The speed of air flow on the upper and lower surfaces of a wing of an aeroplane are v₁ and v₂ respectively. If A is the cross section area of the wing and is the density of air, then the upward life is
Options
- A1 2 A (v₂-v₁ )
- B1 2 A (v₁+v₂ )
- C1 2 A (v₁^2-v₂^2 )
- D1 2 A (v₁^2+v₂^2 )
Correct answer
C. 1 2 A (v₁^2-v₂^2 )
Step-by-step solution
( aligned E_ rotational & .= 1 2 , ^2 & = L ^2 2 ( L = ) aligned ) Therefore, ( L ^2=2 EI ) Hence (L_A^2=2 E_A I_A ) ...(i) and (L_B^2=2 E_B I_B ) ...(ii) From equation (i) and (ii) ( aligned L_A L_B & = 2 E_A I_A 2 E_B I_B & = 100 4 L_A L_B & =5 ( E_B E_A . & .=100 and I_A I_B =4 ) aligned )