Author Question: A distant galaxy is emitting light from the helium spectrum at 388.9 nm. On Earth the wavelength of ... (Read 52 times)

robinn137

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A distant galaxy is emitting light from the helium spectrum at 388.9 nm. On Earth the wavelength of the light from this galaxy is measured to be 540.6 nm.
 
  Estimate how far from Earth (in light-years) this galaxy is if the Hubble constant has the value 22 km/s per million light-years. (c = 3.00  108 m/s, 1 ly = 9.461  1015 m, 1 y = 3.156  107 s)

Question 2

If you take a given pendulum to the Moon, where the acceleration of gravity is less than on Earth, the resonant frequency of the pendulum will
 
  A)
 
  increase.
  B)
 
  decrease.
  C)
 
  not change.
  D)
 
  become zero.
  E)
 
  either increase or decrease; it depends on its length to mass ratio.



Dnite

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Answer to Question 1

4.3  109 ly

Answer to Question 2

B



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