One of the new events in the 2002 Winter Olympics was the sport of skeleton (see
ID: 1451024 • Letter: O
Question
One of the new events in the 2002 Winter Olympics was the sport of skeleton (see photo). 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 123 m in elevation from top to bottom.
(a) In the absence of nonconservative 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.
m/s
(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 81.3-kg rider and skeleton by nonconservative forces?
Explanation / Answer
Here ,
height dropped , h = 123 m
a)
let the speed at the bottom is v
Using conservation of energy
0.5 * m * v^2 = m * g * h
0.5 * v^2 = 9.8 * 123
v = 49.1 m/s
the soeed of rider is 49.1 m/s
b)
mass of rider . m = 81.3 Kg
speed at the bottom , v2 = 35.8 m/s
work done by non conservative force = decrease in kinetic energy
work done by non conservative force = 0.5 * 81.3 * 35.8^2 - 0.5 * 81.3 * 49.1^2
the work done by non conservative force = -45900 J
the work done by non conservative force is -45900 J
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