Given that $\mathrm{V}_{\max (\mathrm{P})}=2 \mathrm{v} \quad[\because \omega=2 \pi \mathrm{b},$

$\mathrm{A} \omega=2 \mathrm{v}$    and $\mathrm{k}=2 \pi \mathrm{c}$

${\rm{A}}\omega  = 2\left( {\frac{{\rm{b}}}{{\rm{c}}}} \right),\quad {\rm{v}} = \frac{\omega }{{\rm{k}}} = \frac{{\rm{b}}}{{\rm{c}}}]$

$\Rightarrow a(2 \pi b)=\frac{2 b}{c}$

$\Rightarrow \mathrm{a} \pi=\frac{1}{\mathrm{c}}$

$\Rightarrow c=\frac{1}{\pi a}$