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Fundamentals of Stress and Vibration                1. Mathematics for Structural mechanics
                 [A Practical guide for aspiring Designers / Analysts]


               Assume the magnitude of vector  V  to be′v′.
               Let the inclination of the vector   V  with respect to the vertical axis ‘z’, be ‘θ’. Therefore,

               its inclination to the ‘x − y’ plane is  90 –  θ . The vector is contained in the plane ‘ABCD’ as shown.


               Projection of vector  V  on the ‘z − axis’ is ‘AD’           .      , and, projection of vector  V  on the

               ‘x − y’ plane is ‘DC’ [         .     ].
















                   [Fig 1.20: Vector projection onto 'z-axis']   [Fig 1.21: vector projection onto 'x-y'plane]


                ͳǤͷǤͶ  †‡”•–ƒ†‹‰ –Ї  ‘…‡’– ‘ˆ  ”‘Œ‡…–‹‘


                Consider a vector ( x    ) being projected onto the horizontal axis, as shown in [         .     ].







                 [Fig 1.22: Vector resolution]

               By trigonometry, the magnitude of  ((x    )) is given by:
                                                    1

                         x
                cosϕ =   1    ,  therefore, we have           x      =  x   cosϕ
                         x                               1









                              QP No. SSC/Q4401, Version 1.0, NSQF Level 7, Compliant with Aero and Auto Industries,   Page 25
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