Question

A particle constrained to move along X–axis is subjected to a force in same direction varying with the distance x of the particle from the origin as F(x) = -kx + ax³. k and ‘a’ are positive constants. The functional form of the potential energy U(x) of the particle for x < 0 is best represented is the graph.

Answer 1

Correct option is 4

As F(x) = 0 at x = 0; the slope of potential energy should be zero at x = 0.

∴ The must appropriate option is (4).