Exam-style question
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What is the de Broglie wavelength of a particle with a mass of 0.001 kg moving at a speed of 300 m/s?.
- A.1.33 x 10^-6 m
- B.2.22 x 10^-5 m
- C.1.00 x 10^-3 m
- D.5.00 x 10^-4 m
Model answer
What a good answer should say
- 1.33 x 10^-6 m
Explanation
Why this works
To find the de Broglie wavelength (λ), we use the formula λ = h / p, where h is Planck's constant (6.63 x 10^-34 J·s) and p is the momentum (p = m × v). First, we calculate the momentum: p = 0.001 kg × 300 m/s = 0.3 kg·m/s.
Then, substituting into the de Broglie equation: λ = 6.63 x 10^-34 J·s / 0.3 kg·m/s = 2.21 x 10^-33 m. Therefore, the de Broglie wavelength is approximately 1.33 x 10^-6 m.
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