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 #theta# with the direction in which we are to find it's projection and it's magnitude #A#, the projection is given as #A cos theta#.

  • 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 #theta# 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 theta# , 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 * d#

    Which can be written concisely as,

    #W# = 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 #A# along a direction with which the vector A makes an angle #theta#, the projection is given as, #A Cos theta#

  • Answer:

    Please see the explanation below

    Explanation:

    The vector projection of #vecb# onto #veca# is

    #proj_(veca)vecb=(veca.vecb)/(|veca|^2)veca#

    Calculate the dot product

    #=veca.vecb#

    and calculate the modulus of #veca#

    #=||veca||#

Questions