The momentum of a photon of wavelength lambda is
Correct answer: A. h divided by lambda
- A. h divided by lambda
- B. h times lambda
- C. zero, since a photon has no mass
- D. mc
Explanation
A photon has zero rest mass but still carries momentum h over lambda, which is what allows radiation pressure and the recoil seen in the Compton effect. Solar sails are propelled by exactly this momentum transfer. Assuming that no rest mass means no momentum is the standard misconception here.
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About Photons and the Particle Model of Light
The particle model treats light as photons with energy E equals hf and momentum related to wavelength. Questions involve the photoelectric effect, work function, threshold frequency, stopping potential and photon energy, while distinguishing particle behaviour from the wave description of interference and diffraction.
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