Chapter 4, Problem 60P

A centripetal-acceleration addict rides in uniform circular motion with radius r = 3.00 m. At one instant his acceleration is $\stackrel{\to }{a}=(6.00{\text{ m/s}}^2\text{) <mover accent="true"> i <mo> ^ </mo> </mover> + (}-4.{\text{00 m/s}}^2\text{) <mover accent="true"> j <mo> ^ </mo> </mover>}$. At that instant, what are the values of (a) $\stackrel{\to }{v}$ · $\stackrel{\to }{a}$ and (b) $\stackrel{\to }{r}$ × $\stackrel{\to }{a}$?