(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Deriv µs = tan θ

For when a block is put on a wooden plank and the plank is lifted at one side.

2. Relevant equations

tan = sin/cos

Ff = µFn

3. The attempt at a solution

Ff = µFn

-mgsinθ= µ (-mgcosθ)

µ =(-mgsinθ) /(-mgcosθ)

µ = tan θ

Where i am confused is why Ff = -mgsinθ. Is it because the block has an acceleration of zero when falling down the plank?

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Homework Help: Deriving µs = tan θ

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