stellar temperatures and fluxes: (a) if a spherical star located at a distance d subtends a solid angle ω on the sky, and the flux from the star (integrated over all wavelengths) just above the earth's atmosphere is f(d), show that the flux at the star's photosphere (emitting surface) is π/(d)/q. (b) derive an expression for the surface temperature of a spherical star, in terms only of its at earth, and solid angle ω, its flux per unit wavelength fah) at one wavelength fundamental constants (e) the star betelgeuse has a measured angular diameter of 0.044 arcseconds, and a measured bolometric apparent magnitude of -1.00. use the sun's physical quantities, including its bolometric absolute magnitude from the constants sheet handout, to estimate the surface temperature of betelgeuse in k using the stefan-boltzmann law. (hint: write your equations in terms of ratios between betelgeuse and the sun.)

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.

the right answer is 0.3 meters per second

radial fractures in a piece of glass look most like which of the following?

a. spokes of a wheel

b. a circle

c. a zig zag

d. none of the above

the correct answer is a. spokes of a wheel

hope this (: