A wind with speed 40 m/s blows parallel to the roof of a house. The area of the roof is 250 m2. Assuming that the pressure inside the house is atmospheric pressure, the force exerted by the wind on the roof and the direction of the force will be:
(Pair=1.2kg/m3)
2.4 x 105 N, upwards
2.4 x 105 N, downwards
4.8 x 105 N, downwards
4.8 x 105 N, upwards
As we learnt in
Bernoulli's Principle -
The total energy (Pressure energy, Potential energy and Kinetic energy ) per unit volume or mass of an incompressiable and non viscous fluid in steady flow through a pipe remains constant.
- wherein
Force acting on the roof
Since pressure inside the roof is more than outside so the force will be upward.
Correct option is 1.
Option 1)
2.4 x 105 N, upwards
Correct
Option 2)
2.4 x 105 N, downwards
Incorrect
Option 3)
4.8 x 105 N, downwards
Incorrect
Option 4)
4.8 x 105 N, upwards
Incorrect