Derivation of the Navier–Stokes equations equation), three important concepts may be concisely written: conservation of mass, conservation of momentum, and conservation of energy. Validity is retained if formula_5 is a vector, in which case the vector-vector product in the second term will be a dyad. A general momentum equation is obtained when the conservation relation is applied to momentum. If the intensive property formula_5; considered is the mass flux (also "momentum density"), i.e. the product of mass density and flow velocity formula_17, by substitution in the general continuum equation: where formula_19 is a dyad, a special case of tensor product, which results in a second
Locating the center of mass Locating the center of mass There are several methods for locating the center of mass of a body. This method is useful when one wishes to find the centroid of a complex planar shape with unknown dimensions. It relies on finding the center of mass of a thin body of homogeneous density having the same shape as the complex planar shape. This is a method of determining the center of mass of an L-shaped object. This method is useful when one wishes to find the location of the centroid or center of mass of an object that is easily divided