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John K
John K asked in Science & MathematicsPhysics · 1 decade ago

wavelength and energy of a photon?

A photon has an energy E and wavelength lambda before scattering from a free electron. After scattering through a 140 angle, the photon's wavelength has increased by 11.0%.

Find the initial wavelength of the photon in pm.

Find the initial energy of the photon in fJ.

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  • eduardomoo
    1 decade ago
    Favorite Answer

    This is a question about conserved quantities. Think about this:

    1) For the photon + electron system, is momentum conserved before and after the collision?

    2) For the photon + electron system, is energy conserved before and after the collision?

    Hints: the electron is infinitely massive relative to the photon. Momentum p = h/lambda and kinetic energy = p^2/(2*m).

  • Anonymous
    7 years ago

    Hi,

    A good link to download Photon is: http://bit.ly/1k3tPwW

    I strongly recommend it.

    Best

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