4. A box ofm = 1 kg starts from rest at position A as shown on the diagram, slides downl the frictionless ramp AB, then moves along the rough area BC before going up the frictionless ramp CD. IfH = 5 m, h: 2 m, s = 3m, k: 1000 N/m and pk: 0.5: a) Find the speed of the object at point D immediately before it touches the spring. (4 marks) b) Calculate the maximum compression of the spring. (4 marks) c) The object may move multiple times back and forth along the rough section BC and up the ramps. How far from point B along the section BC will the object finally come to rest? (4 marks}