Question

A body of mass x kg is moving with a velocity of $100~\text{m s}^{-1}$. Its de-Broglie wavelength is $6.62\times10^{-35}$ m. Hence, x is ($h=6.62\times10^{-34}$ Js)

• A. 0.1 kg
• B. 0.25 kg
• C. 0.15 kg
• D. 0.2 kg

Hint:

$\lambda = h / p = h / (mv)$.

Answer 1

The Correct Option is A

Step 1: Formula
Use the de-Broglie wavelength formula: $\lambda = \frac{h}{mv}$.
Step 2: Rearrangement
$m = \frac{h}{\lambda v}$.
Step 3: Substitution
$x = \frac{6.62 \times 10^{-34}}{6.62 \times 10^{-35} \times 100}$.
Step 4: Calculation
$x = \frac{10}{100} = 0.1$ kg.
Final Answer: (a)