Engineering Statics

B-8


  Given the vectors Q = -i + 4j - 6k and S = i + 3j + 5k, compute the vector product for Q and S.

To obtain the vector or cross product, set up a determinant where 
the first row are the unit vectors i, j and k, the second row, the 
components of Q in the x, y and z order and the third row the x, y 
dand z components of S.
To solve the determinant it is expanded by minors, hence i times 
4(5)-(-6)(3) -j times (-1)(5)-(-6)(1) + k times (-1)(3)-(4)(1).  Note 
that it is +i, -j and +k.