Question

When forces $F_{1}, F_{2}, F_{3}$ are acting on a particle of mass $m$ such that $F_{2}$ and $F_{3}$ are mutually perpendicular, then the particle remains stationary. If the force $F_{1}$ is now removed then the acceleration of the particle is

• A. $F_{1}/m$
• B. $F_{2}F_{3}/mF_{1}$
• C. $(F_{2}-F_{3})/m$
• D. $F_{2}/m$

Answer 1

Answer: (A)

For equilibrium of system, $F_{1}=\sqrt{F_{2}^{2}+F_{3}^{2}}$ As $\theta=90^{\circ}$
In the absence of force $F_{1}$,
Acceleration $=\frac{\text{Net force}}{\text{Mass}}$
$=\frac{\sqrt{F_{2}^{2}+F_{3}^{2}}}{m}$
$=\frac{F_{1}}{m}$