Question

The Bernoulli effect can have important consequences for the design of buildings. For example, wind can blow around a skyscraper at remarkably high speed, creating low pressure. The higher atmospheric pressure in the still air inside the buildings can cause windows to pop out. As originally constructed, the John Hancock building in Boston popped window panes, which fell many stories to the sidewalk below.

(a) Suppose that a horizontal wind blows in streamline flow with a speed of 10.3 m/s outside a large pane of plate glass with dimensions 3.00 m ✕ 1.60 m. Assume the density of air to be uniform at 1.30 kg/m³. The air inside the building is at atmospheric pressure. What is the total force exerted by air on the window pane?
N outward
(b) If a second skyscraper is built nearby, the air speed can be especially high where wind passes through the narrow separation between the buildings. Solve part (a) again if the wind speed is 20.6 m/s, twice as high.
kN outward

Answer 1

a)

Pressure inside is

Applying Bernoulli's equation at the window pane,

Pressure out side is  

Force exerted by air on the window pane is  

outward.

b) If the wind speed is twice,

Force exerted on window pane is   outward..