Mathematics

Problem

s=s(t)

denotes the displacement of a particle along a straight line, which of the following represents its acceleration at time

t

? a)

\displaystyle \frac{s}{t^{2}}

\displaystyle \tfrac12\,\dfrac{d^{2}s}{dt^{2}}

\displaystyle \frac{d^{2}s}{dt^{2}}

\displaystyle \frac{1}{t}\,\frac{ds}{dt}