I have a box at rest on a plane raised to the critical angle.(adsbygoogle = window.adsbygoogle || []).push({});

I need to derive the formula [tex]\mu_s=mgtan(\theta)[/tex]

I know [tex]f_s/n=\mu[/tex]

[tex]n=f_y=mgcos(\theta)[/tex]

[tex]f_s=f_x=mgsin(\theta)[/tex]

This leaves me with [tex]tan(\theta)=\mu[/tex] cause the mg cancel out.... what did I do wrong?

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# How to derive coefficient of friction?

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