The Magnitude of a Particle’s Vector#

Question Text#

A particle has a trajectory given as $$\vec{r} = ($$ $$-9t^2 + 5t$$ $$) \hat{\imath} + ($$ $$-9t^2 + 3t$$ $$) \hat{\jmath}$$ $$m$$ for $$t$$ given in seconds. What is the magnitude of the acceleration vector for this particle at $$t =$$ $$17$$ $$s$$?

Please enter in a numeric value in $$m/s$$.