Question

Problem 3. Evan Lysacek and Elvis Stojko, two of the best ice skaters, are challenging each other. They want to try something new on the ice using a spring. But before doing so, they want to test the spring to see if its stiffness is suitable or not. Stojko was scared to try it, so Lysacek went for it. The experiment goes as follows... Lysacek skates with a constant speed at 1 m/s until he reaches a point at which he grabs the spring and slides freelv until he comes to rest. Assume the static Coulomb coefficient of friction for steel blades-ice is us-0.1 and Coulomb kinetic coefficient of friction for steel blades-ice is Lysacek weights 75 kg. Given that the spring's stiffness is 30 N/m, how much time will it take him to come to complete rest? Refer to figure 2 t-0, v(0) 1 m/s, x(0) 0 t«O Figure 2: Lysacek skating at constant speed for t < 0 (in red) then grabs the spring at t- 0 (in blue)

Answer 1

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