4. A block, of mass 0.50 kg, on a horizontal surface with friction is pushed against a spring with a spring constant k so that the spring is compressed by D = 20.0 cm. The block is then released from rest and the spring projects the block along the surface and up a curved incline as shown. Friction does -3.5 J of negative work as the block slides. If the block comes momentarily to rest at height 4 = 2.5 m above the horizontal surface, what is the spring constant k? Uncompressed spring length \\ k h e D A) k=762 N/m B) k=792 N/m C) k=827 N/m E) k=788 N/m