physics

A hydrogen atom, when vigorously perturbed, can emit light with a frequency of 6.16 × 1014 Hz. When the same light from hydrogen atoms in a distant galaxy is observed on earth, the frequency is 5.21 × 1014 Hz. Calculate the speed at which the galaxy is receding from the earth (in units of the speed of light, c).

  1. 👍 0
  2. 👎 0
  3. 👁 105
asked by Joan
  1. Since v is much less than c, you can use the approximate formula

    (delta f)/fo = 0.95*10^14/6.16*10^14
    = 0.154 = v/c

    v = 0.154 c = 4.6*10^7 m/s

    There is an exact formula for the relativistic Doppler shift of light, but I don't believe they expect you to know it. You can find it at

    http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/reldop2.html

    1. 👍 0
    2. 👎 0
    posted by drwls

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics--please help!!

    A hydrogen atom, when vigorously perturbed, can emit light with a frequency of 6.16·1014 Hz. When the same light from hydrogen atoms in a distant galaxy is observed on earth, the frequency is 5.76·1014 Hz. Calculate the speed at

    asked by Kelly on May 6, 2013
  2. Chemistry

    An electron initially in the n = 2 energy level in a hydrogen atom absorbs a photon of light with a frequency of 6.167 x 1014 s-1. Calculate the new energy level the electron will occupy. I am not sure how to being.

    asked by Kim on April 8, 2017
  3. Physics

    A certain type of laser emits light that has a frequency of 4.7 1014 Hz. The light, however, occurs as a series of short pulses, each lasting for a time of 2.8 10-11 s. (a) How many wavelengths are there in one pulse? (b) The

    asked by Anonymous on April 25, 2013
  4. Science

    A certain type of laser emits light that has a frequency of 4.0 × 1014 Hz. The light, however, occurs as a series of short pulses, each lasting for a time of 2.3 × 10-11 s. (a) How many wavelengths are there in one pulse? (b)

    asked by E on April 30, 2019
  5. physics

    An excited atom emits a photon of a certain frequency. Then two photons of this frequency fly towards the atom. Which of the following is likely to happen next? 1. An atom will emit another photon of the same frequency. 2. The

    asked by zachary on April 24, 2018
  6. physics

    An excited atom emits a photon of a certain frequency. Then two photons of this frequency fly towards the atom. Which of the following is likely to happen next? 1. An atom will emit another photon of the same frequency. 2. The

    asked by Lyndsay on April 24, 2018
  7. chemistry

    determine the end value of n in a hydrogen atom transition if the electron starts in n=2 and the atom absorbs a photon of light with a frequency of 4.57 times 10^14 Hz

    asked by will on July 5, 2010
  8. Chem

    Calculate the frequency associated with light of wavelength 656nm. (this corresponds to one of the wavelengths of light emitted by the hydrogen atom.)

    asked by Lauren on November 1, 2007
  9. chemistry

    When electrons move from the fourth energy level to the second energy level, they emit visible light. Explain why the light emitted when an electron makes this move in a sodium atom is a different color that the light emitted by

    asked by Allura on November 21, 2011
  10. chemistry

    help needed in drawing the diagram to show how hydrogen has numerous spectral lines I also need help with this question.... ---------------- ---------------- ---------------- ---------------- ---------------- --------------------

    asked by ruby on February 6, 2007

More Similar Questions