The resultant vertical force exerted on a body by a static fluid in which it is submerged or floating. The buoyant force F_B acts vertically upward, in opposition to the gravitational force that causes it. Its magnitude is equal to the weight of fluid displaced, and its line of action is through the centroid of the displaced volume, which is known as the center of buoyancy. With V the displaced volume of fluid and γ the specific weight of fluid (weight per unit volume), the buoyant force equation becomes F_B = γV. The magnitude of the buoyant force must also be given by the difference of vertical components of fluid force on the lower and upper sides of the body.