A 0.35 kg block rests on a frictionless horizontal surface, where it is attached to a massless spring whose k-value equals 25.0 n/m. let x be the displacement, where x = 0 is the equilibrium position and x > 0 when the spring is stretched. the block is pushed, and the spring compressed, until xi = −4.00 cm. it then is released from rest and undergoes simple harmonic motion.

Find the magnitude of the displacement (in cm) at which the block moves with one-half of the maximum speed. |x| = ____ cm