Halliday, Resnick & Walker — Motion in Two and Three Dimensions: Problem 98

A particle is in uniform circular motion about the origin of an $xy$ coordinate system, moving clockwise with a period of $7.00\text{ s}$. At one instant, its position vector (measured from the origin) is $\vec{r} = (2.00\text{ m})\hat{i} - (3.00\text{ m})\hat{j}$. At that instant, what is its velocity in unit-vector notation?