Based on Heisenberg's uncertainty principle, the uncertainty in the velocity of the electron to be found within an atomic nucleus of diameter $10^{-15} \mathrm{~m}$ is $\_\_\_\_$ $\times 10^9 \mathrm{~ms}^{-1}$ (nearest integer) [Given : mass of electron $=9.1 \times 10^{-31} \mathrm{~kg}$, Plank's constant $(\mathrm{h})=6.626 \times 10^{-34} \mathrm{Js}$ ]
(Value of $\pi=3.14$ )