The equation of a longitudinal stationary wave in a metal rod is...

The equation of a longitudinal stationary wave in a metal rod is given by, $y=0.002 \sin \frac{\pi x}{3}$. $\sin 1000 \pi \mathrm{t}$ where x and y are in cm and t is in seconds. Maximum change in pressure (the maximum tensile stress) at the point $x=2 \mathrm{~m}$, (if young's modulus of the material is $\frac{3}{8 \pi} \mathrm{dynes} / \mathrm{cm}^2$ ) is $\frac{1}{p} \times 10^{-3} \mathrm{dy} / \mathrm{cm}^2$. Find p