Question

The variation of potential energy $U$ of a body moving along $x-$axis varies with its position $\left(x\right)$ as shown in figure
The body is in equilibrium state at:

• A. A
• B. B
• C. C
• D. Both A & C

Answer 1

The correct option is B B

At position B:
$\frac{dU}{dx}=0$
Thus Slope of U - x curve is zero here.
We know that the internal conservative force acting on body is given by,
$F=\frac{-dU}{dx}$
$\Rightarrow F=0$ at $B$, hence it is a position of equilibrium for body.