please help

9. The figure below shows a roller coaster. The 500 kg carriage is starting from stationary at B and rolls along the track, past position D. At position D, it is clocked at 13m/s. D 35 m 20 m a. Complete the calculations to determine Ep and Ek at both positions (B and D). Show work. b, How much energy was "lost" overall from location B to D? Show work starting with Ebefore=Eafter. c. What is the efficiency of this coaster in travelling from B to D