A proton with a kinetic energy of $2.0 \mathrm{eV}$ moves into a region of uniform magnetic field of magnitude $\frac{\pi }{2}\times {10}^{-3} \mathrm{T}$. The angle between the direction of magnetic field and velocity of proton is ${60}^{\mathrm{o}}$. The pitch of the helical path taken by the proton is ____ $\mathrm{cm}$. (Take, mass of proton $=1.6\times {10}^{-27} \mathrm{kg}$ and charge on proton $=1.6\times {10}^{-19} \mathrm{C}$).