Question

There are three forces acting on an object : 6 N to the left ,5 N to the right , and 3 N to the left.What is the net force acting on the object?

• A. 4 N
• B. 4 N left
• C. 4 N right
• D. 8 N left
• E. None of above

Answer 1

The correct option is B 4 N left

Take right side is toward positive, x-axis.

${\overrightarrow{F}}_1=6(-\hat{i})N,{\overrightarrow{F}}_2=5\hat{i}Nand{\overrightarrow{F}}_3=3(-\hat{i})N$

${\overrightarrow{F}}_{net}={\overrightarrow{F}}_1+{\overrightarrow{F}}_2+{\overrightarrow{F}}_3=-6\hat{i}+5\hat{i}-3\hat{i}=4(-\hat{i})N$

Hence, force is $4N$ toward left.