$\begin{aligned} & \Delta v=90 \times \frac{5}{100} \\ & =4.5 \mathrm{~m} / \mathrm{s} \\ & \Delta v . \Delta x=\frac{\mathrm{h}}{4 \pi \mathrm{~m}} \\ & \Delta x=\frac{\mathrm{h}}{4 \pi \mathrm{~m} . \Delta \mathrm{v}} \\ & =\frac{6.63 \times 10^{-34}}{4 \times 3.14 \times 0.01 \times 4.5} \\ & =1.17 \times 10^{-33}\end{aligned}$