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## Homework Statement

A young skier (25kg) pushes off with ski poles to give herself an initial velocity of 3.5 m/s down a hill with 5

^{o}slope with a coefficient of friction of 0.20.

Find the time until skier comes to stop and her displacement.

Therefore

m = 25kg

v

_{i}= 3.5m/s

[tex]\theta[/tex] = 5

^{o}

[tex]\mu[/tex] = 0.20

## Homework Equations

All kinematic-based equations

Newton's Laws (specifically [tex]\stackrel{\rightarrow}{F}[/tex] = m([tex]\Delta[/tex][tex]\stackrel{\rightarrow}{v}/[/tex][tex]\Delta[/tex]t)

F

_{F}= [tex]\mu[/tex]F

_{N}

## The Attempt at a Solution

My idea for this was to find the F

_{NET}and sub that into Newton's Second Law, solving for [tex]\Delta[/tex]t (assuming that [tex]\stackrel{\rightarrow}{v}[/tex]

_{f}is zero)

My solution for [tex]\Delta[/tex]t was 1.3 seconds, correct to two significant digits (to me, that seems quite off)

For the second half of the question, finding the distance, I used [tex]\Delta[/tex][tex]\stackrel{\rightarrow}{d}[/tex] = [tex]\stackrel{\rightarrow}{v}[/tex]

_{i}+ [tex]\frac{1}{2}[/tex][tex]\stackrel{\rightarrow}{a}[/tex]([tex]\Delta[/tex]t)

^{2}using [tex]\stackrel{\rightarrow}{a}[/tex] as the component force of gravity acting parallel to the hill and I got 23m, correct to 2 significant digits.

I was then told I completed the question completely wrong. Now I'm lost. What was I supposed to do?