The photon when scattered from a mirror, its change in momentum becomes _.
Correct answer: A. Double
- A. Double
- B. Half
- C. Remain same
- D. Zero
Explanation
When a photon is scattered from a mirror, its momentum becomes double. This can be explained using the law of reflection, which states that the angle of incidence is equal to the angle of reflection. When a photon is scattered from a mirror, its direction changes, but its speed remains constant (since it's in a vacuum). Since momentum is the product of mass and velocity, and the mass of a photon is constant, its momentum is directly proportional to its velocity. When the photon's direction changes upon reflection, its velocity component perpendicular to the mirror's surface remains constant, but the component parallel to the surface reverses direction.
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About Dawn of Modern Physics
Classical physics cannot explain blackbody radiation and related observations, leading to Planck’s quantum theory, in which energy is emitted or absorbed in discrete packets. Photons provide the particle model of light, with energy and momentum linked to frequency and wavelength, including the photoelectric effect and its threshold frequency.
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