Answer
magnitude = $\sqrt(89) = 9.43m $
Work Step by Step
The magnitude of a vector is found by the following:
magnitude = $\sqrt (x^2 +y^2+z^2) $
where the x, y and z represent the x, y and z components (i, j and k) respectively.
In part 1, we found that the position vector in this case is
r = -5m i + 8m j
Therefore we have x = -5 and y = 8 and z = 0
Plugging these in we have
magnitude = $\sqrt ((-5)^2 +8^2+0^2) = \sqrt(25+64) = \sqrt(89) $
