Question

A block of mass $10kg$ is kept on a rough inclined plane as shown in the figure. A force of $3N$ is applied on the block. The coefficient of static friction between the plane and the block is $0.6$. What should be the minimum value of force $P$, such that the block doesnot move downward ?
(take $g=10m{s}^{-2}$)

• A. 32 N
• B. 25 N
• C. 23 N
• D. 18 N

Answer 1

Answer: (A)

$mg\sin 45^{\circ }=\frac{100}{\sqrt{2}}=50\sqrt{2}$
$\mu mg\cos \theta =0.6\times mg\times \frac{1}{\sqrt{2}}=0.6\times 50\sqrt{2}$
$P=31.28\simeq 32N$