4- A 0.5 kg mass slides on a frictionless rod in a vertical plane as shown. The undeformed length of the spring is lo = 250 mm, the spring modulus is k = 600 N/m, and the distance d = 800 mm. If the slider is released from rest when b = 300 mm, determine the speed of slider at position B and C. {5.85 m/s, 6.49 m/s} Comprehension (State Definition, Free Body Diagram and/or Diagram Sketch) k www m