A 100 kg one-man bobsled starts from rest 50 m from the end of an icy, 15∘ slope. A giant 2.0-m-long spring is placed against a barricade at the bottom of the slope. (Figure 1) shows a coordinate system with the origin at the base of the spring. The bobsled brake fails to work, and the sled crashes into the spring. The spring compresses 75 cm before expanding and shooting the bobsled back up the slope. What is the spring constant of the spring?
