A spring causes a textbook attached to its end to oscillate back and forth. The end of the springs position at time t is defined by the function y = 4.50cos(2.50π t+ 0.500π) meters. The textbook has a weight of 27.5 N. (a) What is the magnitude of the maximum acceleration of the textbook? (b) What is the magnitude of the maximum force the spring exerts on the textbook? (c) State two positions where the force equals zero.