A particle is in uniform circular motion about the origin of an xy coordinate system, moving clockwise with a period of 3.50 s. At one instant, its position vector (from the origin) is r = (8.00 m) ihat - (7.00 m) jhat. At that instant, what is its velocity in unit-vector notation?

Answer 1

The magnitude of the velocity is
|V| = 2 pi R f, where f is the rotation frequency and R is the length of the radius vector. The direction is perpendicular to the radius vector, aimed in the clockwise direction.