Question

If the particle is located slightly to the left of point B, its acceleration is __________.

Answer 1

(1) directed to the right

Explanation:

To the right of B, u(x) is a decreasing function & so its derivative is negative,this implies that the x component of the force on a particle at this position is positive,or that the force is directed towards right .Small deviations from equilibrium at point B causes a force to accelerate the particle away ,hence particle is in unstable equilibrium.