Question

A block of mass $0.1kg$ is held against a wall applying a horizontal force of $5N$ on the block. If the coefficient of friction between the block and the wall is $0.5$. the magnitude of the friction force acting on the block is

• A. $2.5N$
• B. $0.98N$
• C. $4.9N$
• D. $0.49N$

Answer 1

Answer: (B)

$0.98N$

Limiting value of frictional force,

$f_{max}=\mu N=.5\times 5=2.5N$

Now, value of $mg=0.1\times 9.8=0.98N$

$f_{max}>mg$

then frictional force acting on block is

$f=mg=0.98N$