In a new Olympic event athletes run as fast as they can, jump onto a sled, ride it down a hill and compress a spring as far as they possibly can. (who thinks of these any ways) a. Consider a 55.0 kg athlete that makes it to a top speed of 12.5 m/s before jumping onto a 15.0 kg sled. What is the athlete/sled initial speed as she starts down the hill? b. If the hill is 25.0 m long at an angle of 15.0 0 how much mechanical energy does the athlete/sled initially have? c. If the hill has a coefficient of friction of 0.125, what is the speed she reaches at the bottom of the hill, just before hitting the spring? d. Assuming the spring is located just at the bottom, and the coefficient of friction is the same as on the hill, how far could this athlete compress the spring if it has a coefficient of 1250 N/m? I am not sure how to go about this question. I know that you need acceleration for initial speed but can't figure out how to find it with the numbers given.