Final answer:
The air pressure above the roof in a hurricane will be lower than the pressure inside the house due to Bernoulli's principle, which explains the large destructive power of hurricanes as the wind velocity increases.
Step-by-step explanation:
When a hurricane wind blows across a flat roof at high speed, as in the case of a wind speed of 190 km/hr, the air pressure above the roof is lower than the pressure inside the house. This phenomenon is explained by Bernoulli's principle, which states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure. The high-speed wind acting on the roof creates a region of lower pressure compared to the relatively static air inside the house, which can lead to the lifting of the roof if the pressure difference is large enough.
The destructive power of hurricanes can be partly attributed to this principle. With wind velocities exceeding 50 m/s, the force exerted can be significantly damaging due to the cubic relationship between power and wind velocity. This also explains why small drops in atmospheric pressure can lead to severe changes in weather, such as those experienced during hurricanes.