Given below is the plot of a potential energy function U(x) for a system, in which a particle is in one dimensional motion,
Question:

Given below is the plot of a potential energy function U(x) for a system, in which a particle is in one dimensional motion, while a conservative force F(x) acts on it. Suppose that Emech = 8 J, the incorrect statement for this system is :

1. at $\mathrm{x}>\mathrm{x}_{4}, \mathrm{~K}$.E. is constant throughout the region.

2. at $x<x_{1}, K . E$. is smallest and the particle is moving at the slowest speed.

3. at $x=x_{2}, K . E$. is greatest and the particle is moving at the fastest speed.

4. at $x=x_{3}, K . E,=4 J$.

Correct Option: , 2

Solution:

$\mathrm{E}_{\text {mech. }}=8 \mathrm{~J}$

Particle is at rest.

(C) At $x=x_{2}, U=0 \Rightarrow E_{\text {mech. }}=K=8 \mathrm{~J}$

KE is greatest, and particle is moving at fastest speed.