Drag forces are caused by the air molecules that hit the surface of the blade facing the wind. A major component of the drag force acts in the direction that is parallel to the main shaft of the rotor. The magnitude of the drag force varies with the wind speed and the size and shape of the blade Drag forces have a. .
When the wind passes over the blade, the pressure difference between the front and back of the blade causes the lift forces. A major component of the lift. .
The velocity of each particle inside the blade changes direction as the rotor rotates. This change of direction is a form of acceleration of the particle toward the center, or axis, that the blade revolves around This acceleration. .
The gravitational forces acting on any part of the blade vary with the mass density, size, and shape of the blade. The gravitational forces are always toward the center of the earth,.
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