Answer
$$ 20\ \ m/s,\ \ \ -34.64 \mathrm{cm} / \mathrm{s}^{2}$$
Work Step by Step
Given $$s(t) = 300 + 40 \sin t $$
The velocity is given by
\begin{align*}
s'(t)&= 40\cos t\\
s'(\pi/3)&= 20\ \ m/s
\end{align*}
and the acceleration is given by
\begin{align*}
s''(t)&= -40\sin t\\
s''(\pi/3)&= -34.64 \mathrm{cm} / \mathrm{s}^{2}
\end{align*}
