) with a measured

The red-shift of a galaxy observed by us corresponds to a speed of 50000 km/s. How far is the galaxy from us approximately? A. 700 Mpc B. 70 Mpc C. 7 Mpc D. 7 Gpc   Is the answer A? Thank you!

Consider a large interferometer that uses a lazer with the wavelength of 1,073.27 nm (1073.27 x 10-9m). What is the frequency of the photons emitted by this beam in hertz?

in the Cauchy equation if A=1.574 and B=0.0159µm^2 and n=1.642, the wavelength is . 0.4853μm O 485.3nm 438.5nm 0.4385μm 483.5nm O 438.5µm

The most mass of our Milky Way is contained in an inner region close to the core with radius Ro. Because the mass outside this inner region is almost constant, the density distribution can be written as following (assume a flat Milky Way with height zo): Po, r Ro { p(r) : (a) Derive an expression for the mass M(r) enclosed within the radius r. (b) Derive the expected rotational velocity of the Milky Way v(r) at a radius r. (c) Astronomical observations indicate that the rotational velocity follows a different behaviour: VGT pozoRo 5/2 1+e-4r/Ro Vobs (r) Draw the expected and observed rotational velocity into the plot below: 2.0 1.5 1.0 0.5 0.0 1 7 8. 10 Radius from Center r [Ro) (d) Scientists believe the reasons for the difference to be dark matter: Determine the rotational velocity due to dark matter vpM (r) from Ro and draw it into the plot above. (e) Derive the dark matter mass MDM (r) enclosed in r and explain its distributed. (f) Explain briefly three theories that provide…

For a circular velocity profile of the type (r) = αν ar³/6, where a is a constant and is the radial distance from the centre of a spiral galaxy, find the ratio (r)/(r), where (r) is the epicyclic frequency and 2(r) is the angular velocity. Enter your answer to 2 decimal places.

Please put all the equations into the pictures and we’ll explained so I can understand:).

Gauss's law states that fg.dA= -4RGM. A spherical star of mass M and radius R has a uniform density. By applying Gauss's law to a suitable Gaussian surface, show that the magnitude of g within the star rises linearly with radius r. In practice, a star is likely to have a higher density near its center. By referring to Gauss's law, explain in outline what effect this would have on g at a given radius r. Sketch g as a function of r for the above two situations (for r < R and assuming that in both cases the star has the same total mass M).

Whats the wavelength of a photon of light that permits a hydrogen atom to go from its energy level 3 to its energy level 2? 434nm 121.6nm 486.1nm O 656.3nm Whats the wavelength of a photon that could make a hydrogen atom jump from energy level 4 to energy level 2? 656.3nm 121.6nm 102.6nm 486.1nm

A He-Ne laser with wavelength 632.8 nm is fired from a great distance toward a neutron star with mass 4.5 x 1030 kg and radius 12 km. What is the wavelength of light received at the neutron star’s surface?