A block with mass m is in rest on a sledge with mass M andheight h. The sledge can move without friction over the horizontalsurface. Between the sledge and the block is friction withcoefficient of friction ?k. The system starts from rest at time t =0 s. At that instant, there is a spring (constant k, rest lengthl0) between the sledge and the block that is compressed until aquarter of its rest length. Also at that instant, the block m is ata distance d with respect to the edge of the sledge. Then, thespring relaxes and because of this, the sledge and the block startto move. (The spring and the block touch each other, but they arenot attached to each other). a) Determine the velocities of boththe sledge and the block at the instant when the block falls of thesledge. b) What is the distance between the edge of the sledge andthe block at the instant when the block hits the ground? Data: m =0.8 kg, M = 5 kg, h = 0.7 m, ?k = 0.2, k = 100 N/m, l0 = 0.6 m, d =1.2 m.

-1/4+ m d M J I