Question

A cube of weight $20N$ rests on a rough inclined plane having angle of inclination ${37}^{\circ }$. The minimum force necessary to prevent the cube from sliding down the plane is $(\mu =0.5)$

• A. $6N$
• B. $4N$
• C. $8N$
• D. $12N$

Answer 1

The correct option is B $4N$

$f=mg\sin \theta -\mu mg\cos \theta$

$=20(\frac{3}{5}-\frac{2}{5})=4N$