A particle moves counterclockwise in a circular path of 400 ft radius. It starts from a fixed point which is horizontally to the left of the center of the path and moves so that s = 10t2 + 20t where s is the arc distance in ft and t is the time in sec. Compute the (a) velocity at the end of 4 sec (b) x and y components of the acceleration at the end of 4 seconds