- #1

haengbon

- 38

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## Homework Statement

A box weighing 20 kg is on an inclined plane with an angle of 30[tex]\circ[/tex].The coefficient of friction is 0.3. What is the acceleration of the box?

## Homework Equations

Newton's Second law ( I think? )

g= 10 m/s

^{2}

## The Attempt at a Solution

[tex]\sum[/tex]y = 0N

_{F}- W

_{y}sin30[tex]\circ[/tex] = 0

N

_{F}= W

_{y}sin30[tex]\circ[/tex]

N

_{F}= [(20)(10)]sin30[tex]\circ[/tex]

N

_{F}= 100 N

*f*= [tex]\mu[/tex]N

_{F}

*f*= (0.3)(100)

*f*= 30

[tex]\sum[/tex]x = ma

Wcos30[tex]\circ[/tex] + f = m(-a)

20cos30[tex]\circ[/tex] + 30 = -20a

[tex]47.32/-20[/tex] = [tex]-20a/-20[/tex]

a = -2.36 m/s

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Is this correct? :D