A child slides from rest down a playground slide. The top and bottom of the slide are separated by y = 4.0m vertically and x = 7.0m horizontally. A sheet of metal (straight, not curved) connects the two ends of the slide, and the coefficient of friction between the slide's surface and the child's clothes is k = 0.22. What is the child's speed v upon reaching the bottom of the slide? For the limits check, investigate what happens to vf as the slide becomes dangerously steep (x 0). Note: you must use a work/energy approach rather than a kinematics approach to solve this problem.