$5 \sqrt{3}=\mathrm{A\,sin\,k} \times 10$
$5 \sqrt{3}=\mathrm{A} \sin \mathrm{k} \times 20$
After solving $\mathrm{k}=\frac{\pi}{30}$
$5\sqrt 3 = {\mathop{\rm Asin}\nolimits} \left( {\frac{{II}}{{30}} \times 10} \right) \to {\rm{A}} = 10\,{\rm{mm}}$
${y_1} = {10^{ - 6}}\sin [100\,t + (x/50) + 0.5]m$
${y_2} = {10^{ - 6}}\cos \,[100\,t + (x/50)]m$
where $ x$ is expressed in metres and $t$ is expressed in seconds, is approximately .... $ rad$

