The size of a mircroscopic particle is 1 micron and its mass is 6 × 10^–13g. If its position may be measured to within 0.1% of its size, the uncertainity in velocity (in cm^–1) is

$∆\mathrm{x} =\frac{\mathrm{h}}{4\mathrm{\pi m} \times ∆\mathrm{v}}$

 Mass is 6 × 10^–13g. ,The size of a mircroscopic particle == 1 micron =10^-6gm

position measured to within 0.1% of its size

$∆\mathrm{v} =\frac{\mathrm{h}}{4\mathrm{\pi m} \times ∆\mathrm{x}}$

$∆\mathrm{v} =\frac{6.625\times {10}^{-27}}{4\mathrm{\pi }\times 6 \times {10}^{-13}\times 0.1 \times {10}^{-6}}$ = $\frac{{10}^{-7}}{4\mathrm{\pi }}$