6. A single rollercoaster cart with mass of 500 kg is momentarily at rest atop a 25 m drop. It rolls down this first hill to the bottom and then up to a second level elevation. Assuming that the track is frictionless and that the bottom of the first hill is the reference level, determine the rollercoaster cart's: (See diagram below for details) a) total energy atop the first hill (section 1) b) speed at the bottom of the first hill (section 2) c) speed on the second elevation (section 3) Diagram - start at section 1 (v=0 m/s) height unknown Height at section 2 = 25 m Height at section 3 = 20 m