Question

The de Broglie wavelength of 1 mg grain of sand blown by a 20 m/s wind (approxiamately) is:

• A. $4.4\times {10}^{-29}m$
• B. $2.2\times {10}^{-29}m$
• C. $1.1\times {10}^{-29}m$
• D. $3.3\times {10}^{-29}m$

Answer 1

The correct option is D $3.3\times {10}^{-29}m$

Given :
$\text{Planck's constant}\left(h\right)=6.63\times {10}^{-34}Js\text{mass of sand grain}\left(m\right)={10}^{-6}kgv=20m/sec$
$\text{de Broglie wavelength}\left(\lambda \right)=\frac{h}{mv}=\frac{6.63\times {10}^{-34}}{{10}^{-6}\times 20}=3.315\times {10}^{-29}m$