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Intrusionv2

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## Homework Statement

Lindsey's car is driving up a hill when her book bag, which she forgot on the roof, falls off. The bag has a mass of 19kg and slides up the hill 60 meters from its initial speed of 20m/s to rest. If the hill climbs at an angle of 30 degrees then what was the coefficient of friction?

## Homework Equations

Fn = mgcosx

Ff = [tex]\mu[/tex]cosx

F = ma

Vf

^{2}= Vi

^{2}+ 2ad

Fp = mgsinx (?)

## The Attempt at a Solution

Fn = 19*9.8cos30 = 161N

Vf

^{2}= Vi

^{2}+ 2ad

0 = 20

^{2}+ 2a(60)

-400 = 120a

a = -3.33 m/s

^{2}

F = ma

F = 19 * -3.33 = 63.27N

Ff = [tex]\mu[/tex]mgcosx

63.27 = [tex]\mu[/tex]19*9.8*cos30

[tex]\mu[/tex] = .393

Is this correct? Is the parallel component required in this case? In what cases is it required?