Answer
$$s(x, t)=(6.1 \mathrm{nm}) \cos \left[\left(9.2 \mathrm{m}^{-1}\right) x-\left(3.1 \times 10^{3} \mathrm{s}^{-1}\right) t\right]$$
Work Step by Step
The angular frequency is $$\omega=2 \pi / T=3142 \mathrm{rad} / \mathrm{s} \approx 3.1 \times 10^{3} \mathrm{rad} / \mathrm{s}$$
The results may be summarized as $$s(x, t)=(6.1 \mathrm{nm}) \cos \left[\left(9.2 \mathrm{m}^{-1}\right) x-\left(3.1 \times 10^{3} \mathrm{s}^{-1}\right) t\right]$$
