Ablock with mass m = 0.300 kg is attached to one end of an ideal spring and moves on a horizontal frictionless surface. the other end of the spring is attached to a wall. when the block is at x +0.240 m, its acceleration is a (a) the spring's force constant k; (b) the amplitude of the motion; (c) the maximum speed of the block during its motion; and (d) the maximum magnitude of the block's acceleration during its motion? c -12.0 m/s2 and its velocity is v +4.00 m/s.