Question

A body of weight $50N$ placed on a horizontal surface is just moved by a force of $28.2N$. The frictional force and the normal reaction are

• A. $10N,15N$
• B. $20N,30N$
• C. $2N,3N$
• D. $5N,6N$

Answer 1

The correct option is B $20N,30N$

Body Weight $50N\to N$

just moved by $28.2N$

Frictional force and normal reaction

$f_s=\mu N$
$f\cos \theta =\mu N$ (Frictional Force)

$28.2\times \frac{1\times \surd 2}{\surd 2\surd 2}$

$=20N$ (approximately) $(\theta =45)$

So correct option is option B.