Q. The force acting on a body moving along $x$-axis varies with the position of the particle as shown in the fig The body is in stable equilibrium at
A) $x = x_{1}$
B) $x = x_{2}$
C) Both $x_{1}$ and $x_{2}$
D) Neither $x_{1}$ nor $x_{2}$
Explanation
(b) When particle moves away from the origin then at position $x = x_{1}$ force is zero and at $x > x_{1}$, force is positive (repulsive in nature) so particle moves further and does not return back to original position
$i.e.$ the equilibrium is not stable
Similarly at position $x = x_{2}$ force is zero and at $x > x_{2}$, force is negative (attractive in nature)
So particle return back to original position $i.e.$ the equilibrium is stable
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.