Question

A block of mass 1 Kg is plane on a rough inclined plane at angle $\theta ={45}^0$. Will horizontal. The block is connected with a straight as shown in Fig. If $\mu =3/4$, find the tension in string.

Answer 1

Let us first find the angle of response, i.e., the angle of inclination of inclined plane with horizontal such that when a As we know the angle of response,
$\alpha =ta{n}^{-1}\left({\mu }_s\right)=ta{n}^{-1}\left(\frac{3}{4}\right)={37}^0$
Here the angle of inclination of plane is less than the angle of response. Here the block does not have tendency to slide. The friction force between the block and incline is static nature.
$f=mgsin\theta =1\times 10\times sin{30}^0=5N$
Hence, tension in string will be zero.