# Worksheet: Photon Momentum

In this worksheet, we will practice calculating the momentum of a photon given its frequency or wavelength.

**Q1: **

What is the momentum of a gamma-ray photon with a wavelength of m? Use a value of J⋅s for the Planck constant. Give your answer to 3 significant figures.

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

**Q2: **

What is the momentum of a photon that has a wavelength of 500 nm? Use a value of J⋅s for the Planck constant. Give your answer to 3 significant figures.

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

**Q3: **

A solar sail is a proposed method of spacecraft propulsion that uses the momentum of photons as a source of thrust. When photons hit the sail, they are absorbed and their momentum is transferred to the sail. If laser light with a wavelength of 200 nm is used to propel the sail, how many photons must hit the sail for it to gain 1 kg⋅m/s of momentum? Use a value of J⋅s for the Planck constant. Give your answer to 3 significant figures.

- A photons
- B photons
- C photons
- D photons
- E photons

**Q4: **

A laser produces photons, each with a frequency of Hz. What magnitude of momentum does producing these photons impart on the laser? Use a value of J⋅s for the Planck constant. Give your answer to 3 significant figures.

**Q5: **

What is the ratio of the momentum of a photon to its frequency? Use a value of J⋅s for the Planck constant. Give your answer to 3 significant figures.

- A
- B
- C
- D
- E

**Q6: **

The the wavelength of a photon, the its momentum is. The the frequency of a photon, the its momentum is.

- Ashorter, larger, lower, larger
- Bshorter, larger, higher, larger
- Clonger, larger, higher, smaller
- Dlonger, larger, higher, larger
- Eshorter, smaller, higher, smaller

**Q7: **

What is the momentum of an ultraviolet photon with a frequency of 1.5 PHz? Use a value of J⋅s for the Planck constant. Give your answer to 3 significant figures.

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

**Q8: **

The momentum of a photon is to its wavelength and to its frequency.

- Ainversely proportional, inversely proportional
- Binversely proportional, proportional
- Cinversely proportional, equal
- Dproportional, inversely proportional
- Eproportional, proportional

**Q9: **

A low-frequency radio wave has a frequency of 200 kHz. What is the momentum of a radio-wave photon with this frequency? Use a value of J⋅s for the Planck constant. Give your answer to 3 significant figures.

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

**Q10: **

What is the wavelength of a photon that has a momentum of kg⋅m/s? Use a value of J⋅s for the Planck constant. Give your answer to 3 significant figures.

- A 0.754 nm
- B 1.51 nm
- C 0.663 nm
- D 1.33 nm
- E 2.65 nm

**Q11: **

A photon has a momentum of kg⋅m/s. What is the frequency of the photon? Use a value of J⋅s for the Planck constant. Give your answer to 3 significant figures.