Question

Three forces acting on a body are shown in the figure. To have the resultant force only along the y-direction, the magnitude of the minimum additional force needed is

• A. $\sqrt{3}N$
• B. $\frac{\sqrt{3}}{4}N$
• C. $0.5N$
• D. $1.5N$

Answer 1

The correct option is C $0.5N$


Let the additional force F be directed along the positive x-direction
Taking x-components, the total should be zero
$1\cos \left({60}^{\circ }\right)+2\cos \left({60}^{\circ }\right)$
+ F - 4cos(60°) = 0
Therefore, F = 0.5 N