Engineering Statics

B-1


  Given the vectors P = -2i + 3j + 4k, Q = -i + 4j - 6k and S = i + 3j + 5k, compute the scalar product for P and Q.

To obtain the dot product, multiply the x component of the first 
vector with the x-component of the second vector.  Do the same 
for the y and z components.  Since the scalar product of i and i, 
j and j and k and k is 1, and the scalar products of unlike unit 
vectors (ex. i and k) is 0, the three multiplications yield scalars.
Adding the three scalars given the answer of -10. 
Notice that the answer is a SCALAR.