I feel like a fool because I can't get this, but I am simply in need of some guidance re: equation usage. A bobsled run leads down a hill as sketched in the figure above. Between points A and D, friction is negligible. Between points D and E at the end of the run, the coefficient of kinetic friction is µ = 0.4. The mass of the bobsled with drivers is 220 kg and it starts from rest at point A. (Basically, the bobsled is at the top of hill A, which is 50m tall. It then travels to valley B (y=0) and back up to hill C (y=30m). It then proceeds down to D (y=0) where the friction starts until E.) I need to find out the following: -) Find the distance x beyond point D at which the bobsled will come to a halt. I have already determined the velocity at valley B (31.32m/s) and the work done by gravity between A and C. So, the hint says "The work done by friction is the change in kinetic energy minus the work done by gravity between D and E." But how do I get the KE? I can calculate fk (ukN=863.30) and already have Work of gravity). I just need KE. And I can't figure out how to get it, correctly.