Achild rides a merry-go-around while turning with uniform circular motion. at time t 2 s, the child's velocity is vi = (4.5 m/s)î+ (4 m/s)j, measured on a horizontal xy coordinate system. at time t2 7s, a half-revolution later, the child's velocity is v(-4.5 m/s)î + (-4 m/s)j (a) what is the magnitude of the child's average acceleration during the time interval t2-t? (b) what is the child's centripetal acceleration (magnitude of the child's radial acceleration) during the time interval t2 t? (c) what is the child's radial acceleration vector (using î andj) at t2? at time t2, the merry-go-round begins to slow down, coming to a complete stop just as it completes two full rotations after t2- during this time, the child experiences a constant tangential acceleration. (d) what is the magnitude of the child's tangential acceleration during the time it takes the merry-go-round to come to a complete stop?