A mother pushes her child on a swing so that his speed is 8.75 m/s at the lowest point of his path. The swing is suspended 1.95 m above the child's center of mass. (a) What is the magnitude of the centripetal acceleration (in m/s²) of the child at the low point? (b) What is the magnitude of the force (in N) the child exerts on the seat if his mass is 19.1 kg? (c) What is unreasonable about these results?