1. (15pts) A chamber is whirled around horizontally at the end of a shaft. A woman in the chamber places a box of mass m = 7.5 kg against the vertical wall, and pushes against the box with a horizontal force of Fupp = 115 N. The coefficient of static friction between the box and the wall is = 0.20, and the wall is = 12.0 m from the rotation axis. How fast must the wall of the chamber be traveling in order for the box not to slip downward? 12.0 m