Question

A block of weight $5N$ is pushed against a vertical wall by a force $12N$.The coefficient of friction between the wall and block is $0.6$. The magnitude of the force exerted by the wall on block is:

• A. $12N$
• B. $5N$
• C. $7.2N$
• D. $13N$

Answer 1

The correct option is D $13N$

REF. Image.

$\therefore {\left[H_2\right]}_{eq}=\frac{3.2}{2}=1.6mol/lit.$

man value of f possible $=\mu N$

$=0.6\times 12$

$=7.2N$

f required to keep block reactionary $=mg=5N$

$\therefore f=5N$