An umbrella tends to move upwards on a windy day principally because
A)air gets trapped under the umbrella,warms,and rises.
B)buoyancy increases with increasing wind speed.
C)air pressure is reduced over the curved top surface.
D)all of these

Question

Quizplus · Accepted Answer

When wind flows over the top of an umbrella, the curved shape of the surface causes a reduction in air pressure. This creates a lower pressure zone above the umbrella than below it, causing the umbrella to move upwards. The other options do not accurately explain this phenomenon.

An Umbrella Tends to Move Upwards on a Windy Day