Physics

Problem

Which one of the following differential equations correctly represents the displacement

x(t)

of a mass

m

attached to an ideal spring of spring constant

k

on a friction-less horizontal surface? a)

\dfrac{d^{2}x}{dt^{2}}-\dfrac{k}{m}\,x=0

\dfrac{d^{2}x}{dt^{2}}+\dfrac{m}{k}\,x=0

\dfrac{d^{2}x}{dt^{2}}+\dfrac{k}{m}\,x=0

\dfrac{d^{2}x}{dt^{2}}=-k x