# Worksheet: De Broglie Waves

In this worksheet, we will practice calculating the de Broglie wavelength of high-energy particles and macroscopic objects.

**Q2: **

What is the de Broglie wavelength of an electron travelling at a speed of m/s?

**Q4: **

What is the de Broglie wavelength of a proton whose kinetic energy is 10 MeV?

**Q5: **

A proton in an accelerator has an energy of 1.00-TeV.

Find the Lorentz factor for the proton.

Find the DeBroglie wavelength for the proton.

**Q6: **

What is the velocity of a 0.400-kg billiard ball if its wavelength is 7.50 fm?

- A m/s
- B m/s
- C m/s
- D m/s
- E m/s

**Q7: **

At what velocity will an electron have a wavelength of 2.11 m?

- A m/s
- B m/s
- C m/s
- D m/s
- E m/s

**Q8: **

What is the kinetic energy of a 0.0300 nm wavelength electron in a tunneling electron microscope?

**Q9: **

What is the wavelength of an electron accelerated from rest by a 36.7 keV potential difference?

**Q10: **

What is the de Broglie wavelength of a 70 kg football player running at a speed of 6.5 m/s?

- A m
- B m
- C m
- D m
- E m

**Q11: **

At what velocity does a proton with a 5.80 fm wavelength move? Give your answer in units of .

- A
- B
- C
- D
- E

**Q12: **

Find the wavelength of a proton that is movingv at 3.40% of the speed of light.

**Q13: **

What is the de Broglie wavelength of an electron that is accelerated from rest through a potential difference of 16 keV?

- A7.9 pm
- B8.6 pm
- C8.0 pm
- D9.7 pm
- E4.2 pm

**Q14: **

The de Broglie wavelength of a neutron is 0.0500 nm.

What is the speed of this neutron?

What is the energy of this neutron?

- A J
- B J
- C J
- D J
- E J

**Q15: **

An X-ray photon has an energy of 125 keV, and a neutron has the same momentum as the photon.

Find the momentum of the photon.

- A kgβ m/s
- B kgβ m/s
- C kgβ m/s
- D kgβ m/s
- E kgβ m/s

Find the velocity of the neutron with the same momentum.

What is the neutronβs kinetic energy?

- A J
- B J
- C J
- D J
- E J

**Q16: **

A neutron has a wavelength of 5.60 fm.

What is the neutronβs velocity?

- A m/s
- B m/s
- C m/s
- D m/s
- E m/s

What is the neutronβs kinetic energy?