The product of a number m by a vectoris the vector  that it has:

1) direction: The same one that if m is positive
                      Opposite to if m is negative

2) module: the module ofmultiplied by the absolute value of m

If m =0 the vector null vector, is one vector that has module and that one indicates by. That is to say,0=.

Summarizing, to multiply a vector by a number m being equivalent to lengthen (or shrinking) his module as many times as he indicates the absolute value of m, and reverse its direction if m is negative.

The number m by which a vector multiplies one receives the name of scalar.

In the figures of the right you have three examples of a product of a scalar one a vector.

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