Vector Projection

Key Questions

  • A vector is specified by its components along the coordinate axes in a particular coordinate system.
    A vector projection of a vector A along some direction is the component of the vector along that direction.
    If A makes an angle thetaθ with the direction in which we are to find it's projection and it's magnitude AA, the projection is given as A cos thetaAcosθ.

  • Vector projections are used for determining the component of a vector along a direction.

    Let us take an example of work done by a force F in displacing a body through a displacement d.
    It definitely makes a difference, if F is along d or perpendicular to d (in the latter case, the work done by F is zero).

    So, let us for now assume that the force makes an angle thetaθ with the displacement. In this case the component of force along displacement does all the work.
    The component of F along d is F Cos thetaFcosθ , which is nothing other than the projection of F along d.

    Thus, for a general case, work done is given as,

    W = F Cos theta * dW=Fcosθd

    Which can be written concisely as,

    WW = F . d

  • Answer:

    A vector projection along any direction is the component of a given vector along that direction.

    Explanation:

    If we have to determine the vector projection of vector A with modulus AA along a direction with which the vector A makes an angle thetaθ, the projection is given as, A Cos thetaAcosθ

  • Answer:

    Please see the explanation below

    Explanation:

    The vector projection of vecbb onto vecaa is

    proj_(veca)vecb=(veca.vecb)/(|veca|^2)vecaprojab=a.ba2a

    Calculate the dot product

    =veca.vecb=a.b

    and calculate the modulus of vecaa

    =||veca||=a

Questions