1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Crank
3 years ago
15

If you found a galaxy with an Ha emission line that had a wavelength of 756.3 nm, what would be the galaxy’s distance if the Hub

ble constant is 70 km/s/Mpc? (Note that the rest wavelength of the Ha emission line is 656.3 nm.)
Physics
1 answer:
Delicious77 [7]3 years ago
6 0

Answer: 653.011Mpc

Explanation:

Hubble deduced that the farther the galaxy is, the more redshifted it is in its spectrum, and noted that all galaxies are "moving away from each other with a speed that increases with distance", and enunciated the now called Hubble–Lemaître Law.  

This is mathematically expressed as:

V=H_{o}D (1)

Where:

V is the approximate recession velocity of the galaxy

H_{o}=70 km/s/Mpc is the current Hubble constant  

D is the galaxy's distance

On the other hand, the equation for the Doppler shift is:

\frac{\Delta \lambda}{\lambda_{o}}=\frac{V}{c}  (2)

Where:

\lambda_{o}=656.3nm=656.3(10)^{-9}m is the wavelength for the Ha line of the galaxy observed at rest

\Delta \lambda=\lambda_{1}-\lambda_{o} is the variation between the measured wavelength for the Ha emission line in the spectrum of this galaxy (\lambda_{1}=756.3nm=756.3(10)^{-9}m in this case) and the wavelength for the same Ha line observed at rest

c=3(10)^{8}m/s is the speed of light

Rewriting (2):

\frac{\lambda_{1}-\lambda_{o}}{\lambda_{o}}=\frac{V}{c}  (3)

Isolating V:

V=\frac{(\lambda_{1}-\lambda_{o})c}{\lambda_{o}}  (4)

Finding V:

V=\frac{(756.3(10)^{-9}m-656.3(10)^{-9}m)3(10)^{8}m/s}{656.3(10)^{-9}m}  (5)

V=45710802.99m/s=45710.80299km/s  (6)

Substituting V in (1):

45710.80299km/s=(70km/s/Mpc)D (7)

Finding D:

D=\frac{V}{H_{o}}=\frac{45710.80299km/s}{70km/s/Mpc} (8)

Finally:

D=653.011Mpc (8)  This is the galaxy's distance

You might be interested in
Ok ok ik ik this is not the answer but I think you need to hear this
leonid [27]

Answer

oh thanksssss i hope u have a great day

Explanation:

ur a really awesome person and i thank u for that

4 0
2 years ago
What is the periodic symbol for magnesium
Nookie1986 [14]
The periodic sign of magnesium is ------> mg
 
6 0
3 years ago
Read 2 more answers
6. If two objects experience the same net force, but they have different masses, which object will accelerate at
Digiron [165]

Answer:

i would say the heavier object

4 0
3 years ago
Read 2 more answers
A closely wound circular coil has a radius of 6.00 cmand carries a current of 2.65 A. How many turns must it have if the magneti
ad-work [718]

Answer:

Given:

radius of the coil, R = 6 cm = 0.06 m

current in the coil, I = 2.65 A

Magnetic field at the center, B = 6.31\times 10^{4} T

Solution:

To find the number of turns, N, we use the given formula:

B = \frac{\mu_{o}NI}{2R}

Therefore,

N = \frac{2BR}{\mu_{o}I}

N = \frac{2\times 6.31\times 10^{4}\times 0.06}{4\pi \times 10^{- 7}\times 2.65}

N = 22.74 = 23 turns (approx)

 

8 0
2 years ago
Which of Newton’s laws of accounts for the following statement?
Neko [114]
The answer is B


second law
4 0
3 years ago
Other questions:
  • How are humans contributing to climate change?
    7·1 answer
  • A free positive charge released in an electric field will _____
    15·1 answer
  • An electron travels west to east with a kinetic energy of 10 keV. The Earth's magnetic field in Pittsburgh is 19,911.5 nT in the
    9·1 answer
  • A reason that one typically does not notice a blind spot in the visual field is that
    6·1 answer
  • which type of geoscientist interprets data from certain instruments to help detect earthquakes and identify fault lines
    15·2 answers
  • What are some facts about visual memory
    14·2 answers
  • -Two pickup trucks each have a mass of 2,000 kg. The gravitational force between the
    8·1 answer
  • The rates of obesity have more than doubled for children between the ages of 6 and 11 since the middle of the twentieth century.
    15·1 answer
  • What happens to the angle of reflection with respect to the angles of incidence?
    12·1 answer
  • The net external force on the propeller of a 3.8 kg model airplane is 8.2 N forward.
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!