Question

Two force of $12N$ and $8N$ act upon a body. The resultant force on the body has a maximum value of

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

Answer 1

The correct option is C

$20N$

Step 1: Given;

$$\begin{gathered} F_1=12N \\ {F}_2=8N \end{gathered}$$

Step 2: Formula used;

$R=\sqrt{F_1^2+F_2^2+2F_1{F}_2\cos \theta }$

Step 3: Find the maximum resultant force;

For the maximum value, $\cos \theta =1$

$$\begin{gathered} R_{max}=\sqrt{{12}^2+8^2+2\times 12\times 8\times 1} \\ {R}_{max}=\sqrt{400}=20N \end{gathered}$$

Hence, the resultant force on the body has a maximum value of $20N$.

Thus, option C is correct.