Question

Starting at the top of a steep, icy track, a rider jumps onto a sled (known as a skeleton) and proceeds - belly down and head first - to slide down the track. The track has fifteen turns and drops 104 m in elevation from top to bottom. (a) In the absense of non-conservative forces, such as friction and air resistance, what would be the speed of a rider at the bottom of the track? Assume that the speed of the rider at the beginning of the run is relatively small and can be ignored. (b) In reality, the best riders reach the bottom with a speed of 35.8 m/s (about 80 mi/h). How much work is done on an 93.2-kg rider and skeleton by non-conservative forces?

Answer 1

i found that part a) is 45.1 m/s but i don't kno how to find part b)

Answer 2

Wnc=change in energy=ef-eo
=.5mvf^2 - mgh
Should get -32540.68 J