PHYS 3310 Module 4 Activity 2

De Broglie’s Matter Waves

Practice 4.2.1
The speed of proton A is larger than the speed of proton B.  Which one has the longer wavelength?
A. proton A
B. proton B
C. both the same
D. neither has a wavelength
Check your answer: B. proton B
Practice 4.2.2
An electron and a proton have the same speed.  Which one has the longer wavelength?
A. electron
B. proton
C. both the same
D. neither has a wavelength
Check your answer: A. electron
Practice 4.2.3
An electron and a proton are accelerated through the same voltage.  Which one has the longer wavelength?
A. electron
B. proton
C. both the same
D. neither has a wavelength
Check your answer: A. electron

Discuss!

For crystal diffraction experiments, wavelengths on the order of 0.20 nm are often appropriate. Find the energy (in eV) for a particle with this wavelength if the particle is

(a) a photon

(b) an electron

(c) an alpha particle

A neutron is shot straight up with an initial speed of 100 m/s. As it rises, does its de Broglie wavelength increase, decrease, or not change? Explain.