Question

A 41.0-kg skier with an initial speed of 1.5 X 101 m/s coasts up a 2.50-m-high rise as shown below. The coefficient of friction between her skis and the snow is 0.0800. a) Where do you define the gravitational potential energy Ug to equal 0 J? b) If the skier has energy at the bottom of the hill state what kind it is and determine its value. c) If the skier reaches the top of the hill what kind of energy would she have? d) What affect does the friction have on her velocity at the top of the hill, if any? e) Explain what conservation of energy means and how it applies in this situation. BONUS: Determine the skier’s velocity at the top of the hill if she makes it that far, or determine how high up the slope she goes before stopping. (10 points)

Answer #1

given

m = 41 kg

u = 15 m/s

h = 2.5 m

= 0.08

let =35 degree

a) let's take Ug = 0 at the bottom

b) at the bottom the skier has initial velocity = u = 15 m/s

so it has Kinetic energy = KEi = 1/2 m u^{2} = 0.5 x 41
x (15)^{2} = 4612.5 J

c) at the top the skier will have potential energy and kinetic energy

d) friction will reduce the velocity

e

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