Question

Two forces of $12N\text{and}8N$ acts upon a body. The resultant force on the body has maximum value of

• A. $4N$
• B. $0N$
• C. $20N$
• D. $8N$

Answer 1

The correct option is C $20N$

Given,

$|{\overrightarrow{F}}_1|=12N$

$|{\overrightarrow{F}}_2|=8N$

The resultant force on the body is

$|\overrightarrow{R}|=\sqrt{F_1^2+F_2^2+2F_1{F}_{2}cos\theta }$

For maximum value, $cos\theta =1$

$|\overrightarrow{R}|=\sqrt{(12{)}^2+(8{)}^2+2\times 12\times 8\times 1}$

$|{\overrightarrow{R}}_{max}|=\sqrt{144+64+24\times 8}$

$|{\overrightarrow{R}}_{max}|=\sqrt{400}=20N$

The correct option is C.