Solve the each part of given question:

Question: A cat rides a merry-go-round while turning with uniform circular motion. At time t1 = 2.00 s, the cat's velocity is v with arrow1 = (3.20)i hat + (4.00 m/s)j hat, measured on a horizontal xy coordinate system. At time t2 = 4.00 s, a half-revolution later, its velocity is v with arrow2 = (-3.20 m/s)i hat + (-4.00 m/s)j hat.

Part A: What is the magnitude of the cat's centripetal acceleration?

Part B: What is the magnitude of the cat's average acceleration during the time interval t2? t1?

I want to know how to work this out step by step, not just the answer please.