A block is pushed against the spring with spring constant 4.8 kN/m and compresses the spring a distance 5.4cm from its equilibrium position. The block starts at rest, is accelerated by the compression spring, and slides across a frictionless track except for a small rough area on a horizontal section ofthe track. It leaves the track horizontally, flies through the air, and subsequently strikes the ground. What is the speed v of the block when it leaves the track?