(A) at x>x4,U= constant =6J
K=Emech.−U=2J=constant
(B) at x<x1,U= constant =8J
K=Emech.−U=8−8=0J
Particle is at rest.
(C) At x=x2,U=0⇒Emech.=K=8J
KE is greatest, and particle is moving at fastest speed.
(D) At x=x3,U=4J
U+K=8J
K=4J
JEE Main 2021 — Physics Mechanics
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 =8J, the incorrect statement for this system is :

Held on 27 Jul 2021 · Verified 6 Jul 2026.
at x>x4,K.E. is constant throughout the region.
at x<x1,K.E. is smallest and the particle is moving at the slowest speed.
at x=x2,K.E. is greatest and the particle is moving at the fastest speed.
at x=x3,K.E.=4J
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