A 0.550 kg object rests on a frictionless horizontal surface, where it is attached to a massless spring whose k-value equals 21.0 N/m. Let x be the displacement, where x = 0 is the equilibrium position and x > 0 when the spring is stretched. The object is pushed, and the spring compressed, until xi = −4.00 cm. It then is released from rest and undergoes simple harmonic motion
(a) What is the object's maximum speed (in m/s) after it is released? Correct: Your answer is correct. m/s
(b) How fast is the object moving (in m/s) when the spring is momentarily compressed by 1.20 cm (that is, when x = −1.20 cm)? m/s
(c) How fast is the object moving (in m/s) whenever the spring is extended by 1.20 cm (that is, when passing through
x = +1.20 cm)? m/s
(d) Find the magnitude of the displacement (in cm) at which the object moves with one-half of the maximum speed. |x| = cm.