Air is streaming past a horizontal air plane wing such that its speed in `120m//s` over the upward surface and `90m//s` at the lower surface . If the density of air is `1.3kg//m^(3)` and the wing is 10 m long and has an average width of 2m , then the difference of the pressure on the two sides of the wing of ...... Pascal .

Options

A. `4095.0`
B. `409.50`
C. `40.950`
D. `4.0950`

Answer

a

Explanation

Using Bernoulli.s theorem for horizontal pipe ,
`P_(1)+(1)/(2)rhov_(1)^(2)=P_(2)+(1)/(2)rhov_(2)^(2) " " [becauseh_(1)=h_(2)]`
`P_(2)-P_(1)=(1)/(2)rho(v_(1)^(2)-v_(2)^(2))`
`=(1)/(2)xx1.3[(120)^(2)-(90)^(2)]`
`=(1)/(2)xx1.3[14400-8100]`
`=(1)/(2)xx1.3xx6300`
`thereforeP_(2)-P_(1)=4095Pa`