Question

The system shown remains at rest. The force of friction on the block on the slope is:

Answer 1

@ganeshie8 @hartnn can you help me? :)

Answer 2

here, we have to apply the first Newton's law. So we can write this vector equation:
\[\huge {\mathbf{N}} + {\mathbf{W}} + {\mathbf{P}} + {\mathbf{R}} = {\mathbf{0}}\]
where:

\(R\) is the friction force.
From such vector equation, we can write this scalr equation:
\[\Large W - mg\left( {\frac{A}{B}} \right) - \mu mg = 0\]
where \(\Large \mu\) is the friction coefficient and \(\Large A=3,\,B=4\)
Please solve that equation with respect to the coefficient \(\Large \mu\)