Search results
Results From The WOW.Com Content Network
In vector calculus, divergence is a vector operator that operates on a vector field, producing a scalar field giving the quantity of the vector field's source at each point. More technically, the divergence represents the volume density of the outward flux of a vector field from an infinitesimal volume around a given point.
1-forms and 1-vector fields: the 1-form a x dx + a y dy + a z dz corresponds to the vector field (a x, a y, a z). 1-forms and 2-forms: one replaces dx by the dual quantity dy ∧ dz (i.e., omit dx), and likewise, taking care of orientation: dy corresponds to dz ∧ dx = −dx ∧ dz, and dz corresponds to dx ∧ dy.
The vector field corresponding to the example shown. Vectors may point into or out of the sphere. The divergence theorem can be used to calculate a flux through a closed surface that fully encloses a volume, like any of the surfaces on the left. It can not directly be used to calculate the flux through surfaces with boundaries, like those on ...
where x i are coordinates in the moving body. The velocity of each point X i is = +, where ω is the angular velocity vector and v is the derivative of d(t). The work by the forces over the displacement δr i =v i δt of each point is given by
The dotted vector, in this case B, is differentiated, while the (undotted) A is held constant. The utility of the Feynman subscript notation lies in its use in the derivation of vector and tensor derivative identities, as in the following example which uses the algebraic identity C⋅(A×B) = (C×A)⋅B:
Vector calculus or vector analysis is a branch of mathematics concerned with the differentiation and integration of vector fields, primarily in three-dimensional Euclidean space, . [1] The term vector calculus is sometimes used as a synonym for the broader subject of multivariable calculus, which spans vector calculus as well as partial differentiation and multiple integration.
The Helmholtz decomposition in three dimensions was first described in 1849 [9] by George Gabriel Stokes for a theory of diffraction. Hermann von Helmholtz published his paper on some hydrodynamic basic equations in 1858, [10] [11] which was part of his research on the Helmholtz's theorems describing the motion of fluid in the vicinity of vortex lines. [11]
The velocity is a signed quantity: it is positive when ¯ points in the direction of the chosen normal, and negative otherwise. The relationship between Σ t {\displaystyle \Sigma _{t}} and C {\displaystyle C} is analogous to the relationship between location and velocity in elementary calculus: knowing either quantity allows one to construct ...