A force of 750 N is applied to a block of

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A force of $750 \,N$ is applied to a block of mass $102\, kg$ to prevent it from sliding on a plane with an inclination angle $30°$ with the horizontal. If the coefficients of static friction and kinetic friction between the block and the plane are $0.4 $ and $0.3$ respectively, then the frictional force acting on the block is...... $N$

A

$750$

B

$500$

C

$345$

D

$250$

A force of $750 \,N$ is applied to a block of mass $102\, kg$ to prevent it from sliding on a plane with an inclination angle $30°$ with the horizontal. If the coefficients of static friction and kinetic friction between the block and the plane are $0.4 $ and $0.3$ respectively, then the frictional force acting on the block is...... $N$

Net force along the plane = $P - mg\sin \theta $= $750 - 500$= $250\;N$ 

Limiting friction = ${F_l} = {\mu _s}R = {\mu _s}mg\cos \theta $

$= 0.4 × 102 × 9.8 × cos\,30 = 346\, N$

As net external force is less than limiting friction therefore friction on the body will be $250 N.$