Consider a beam of free particles with a certain speed $|\vec{v}|$. If we double this speed, what happens to the beam's de Broglie wavelength?
A) It increases by a factor of 2 .
B) It increases by a factor of $2^{1 / 2}$.
C) It remains the same.
D) It decreases by a factor of $2^{1 / 2}$.
E) It decreases by a factor of 2 .

Question

Quizplus · Accepted Answer

The de Broglie wavelength $\lambda$ is given by $\lambda = \frac{h}{mv}$, where $h$ is Planck's constant, $m$ is the particle's mass, and $v$ is the speed. Doubling the speed $v$ results in the wavelength being halved, so it decreases by a factor of 2.

Consider a Beam of Free Particles with a Certain Speed ∣v⃗∣|\vec{v}|∣v∣

Consider a Beam of Free Particles with a Certain Speed $|\vec{v}|$