Question

A block of mass $4$kg is at rest on an inclined plane making an angle ${30}^o$ with the horizontal. The force of friction between the block and plane is $[g=10m/s^2]$

• A. $10$N
• B. $20$N
• C. $40$N
• D. $20\sqrt{3}$N

Answer 1

Answer: (B)

$20$N

BLock at rest

$f=mg\sin \theta$

$⟹f=4\times 10\times \frac{1}{2}=20N$