Question

How do you compute the dot product to find the magnitude of `u=6j`?

Answer 1

`|| vec u || = 6`

Explanation:

It should be absolutely obvious that `vec u=6 hat j` represents a vector pointing up along `Oy` of `6` units, so theretofore `|| vec u || =6`.

We can show this using the dot product using the fact that:

`|| vec u || = sqrt (vecu * vec u)`

To get

`|| vec u || = sqrt ((6)(6)) =sqrt(6^2)=6`