A cat rides a merry-go-round turning with uniform circular motion. At time t1 = 1.90 s, the cat's velocity is v1=(2.20m/s)i^+(2.70 m/s)j^, measured on a horizontal xy coordinate system. At t2 = 4.60 s, the cat's velocity is v2=(2.20m/s)i^+(2.70 m/s)j^ . What are (a) the magnitude of the cat's centripetal acceleration and (b) the cat's average acceleration during the time interval t2 t1