Question

The de Broglie wavelength of a tennis ball of mass 30 g moving with a velocity of $\text{20}m/s$ is approximately: $\text{(Planck's constant,}h=6.63\times {10}^{-34}Js)$

• A. ${10}^{-31}m$
• B. ${10}^{-16}m$
• C. ${10}^{-25}m$
• D. ${10}^{-33}m$

Answer 1

The correct option is D ${10}^{-33}m$

According to de-Broglie hypothesis,
$\lambda =\frac{h}{mv}$
where,
$h=\text{Planck's constant}m=\text{mass of particle}v=\text{velocity of particle}$

Given:
$h=6.63\times {10}^{-34}Jsm=30g=30\times {10}^{-3}kgv=20m/sec$

Substituting the values,
$\lambda =\frac{6.63\times {10}^{-34}}{30\times {10}^{-3}\times 20}=1.105\times {10}^{-33}m$