The correct option is B The speed of particle is maximum at x = 2m
F=−dUdx=−[5×2x−20]=−10x+20a=Fm=−100x+200=−100(x−2)=−100 X
Where, X=x-2
As a ∝x, so the particle performs SHM
At mean position, X = 0, i.e. x = 2m, so speed of the particle is maximum at x = 2m.
Time period of oscillation is given by, ω2=100
2πT=10⇒T=π5s