Question

Two forces $\overrightarrow{F_1}=3\hat{i}+4\hat{j}$ ${\overrightarrow{F}}_1=3\hat{j}+4\hat{k}$ are acting simultaneously at a point. What is the magnitude of the resultant force?

• A. $50N$
• B. $8.6N$
• C. $\sqrt{74}N$
• D. $\sqrt{50}N$

Answer 1

Answer: (B)

$8.6N$

$a=3i+4j$

$b=3j+4k$

$F_{net}=a+b=3i+7j+4k$

$F_{net}=\sqrt{3^2+7^2+4^2}$

$F_{net}=\sqrt{74}$

$F_{net}=8.60$