Given a graph with a position vector and a vector with velocity, defining another vector. No idea where to start.

Question

Diagram for question, click for image

Hi Please see image link for the question (because there is a diagram) I have no idea to where even start with this! All help appreciated, thanks

Answer 1

Hints: $r(0) = b$. Figure out the radius of the circle of rotation, and use that to determine a parametric formula for $r$ in terms of $\cos t$ and $\sin t$ ($t$ is time). Note that $\omega$ is a constant vector in the same direction as $a$.