A particle moves so that its position vector is given by r=cosωt ^x+sinωt ^y where w is a constant. Which of the following is true?
(a) Velocity and acceleration both are parallel to r.
(b) Velocity is perpendicular to r and acceleration is directed towards to origin
(c) Velocity is perpendicular not and acceleration is directed away from the origin
(d) Velocity and acceleration both are perpendicular to r.