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What evidence do we have that the Great Red Spot of Jupiter is a high pressure region without flowing gas?
Estimate the rate of hydrogen fusion at the sun’s core. You may assume the following:
Average energy emission per hydrogen atom in hydrogen fusion = 6.55 MeV
The luminosity of the Sun = 3.86 ×10^26 J/S
The density of a star varies as d(r) = d(0) {1-(r/R)^2} . Estimate the minimum mass that a star should have to ignite hydrogen fusion at its centre. You may assume that the star is not rotating and the temperature required for hydrogen fusion is 6×10^6 K?
A low mass star evolved as white dwarf with one solar mass and radius equal to 0.9 times the Earth radius. Estimate the escape velocity of the white dwarf and the Gravitational red shit of the carbon spectral line of wave length 700nm.
If the Horizontal component of the electric filed at 15 N/C and vertical component is 21 N/C find the direction (θ) of resultant electric ?.
When the Sun was a protostar, it had a maximum luminosity about 1000 times its present luminosity and a surface temperature about 1000K. What was its radius? Assume that the star radiates like a blackbody.
.The two stars in a binary system have an orbital period of 5 years and an orbital separation, a, of 10AU. What is their combined mass?
In a model of the universe, the Hubble parameter has the following functional form H(z) = H0(1 + z)^(5/4), where H0 is the Hubble constant.

1. Can a spectrograph that operates in the visible region of the electromagnetic spectrum (i.e. 0.38 um to 0.74 um) detect the Hb (H beta) line from a galaxy with a comoving distance D = c/2H0 (c being the speed of light).

2. How long did it take for light to reach an observer, at the present time, from a galaxy that has a redshift z = 2.0? Assume H0 = 67 km/s Mp/c. Express your result in Gyr.
Inflation theory predicts that even the most distant observable parts of the universe should have very similar properties.

Why? Pick one of the answers below which is a crucial part of this explanation.

1)Because of the exponential growth in the size of the universe.
2)Because of spontaneous symmetry breaking.
3)Because of the Higgs field.
4)Because of the unification of the forces of nature.
5).Because of the amplification of quantum mechanical fluctuations
The big rip theory suggest the possibility of the universe being ripped apart by the force of dark energy. With some physicist suggesting it’s going to be too severe to the extend that individual atoms will be ripped off from the universe, leading to a complete annilation but isn’t an exponential expansion and an actual interstellar redshift supposed to mean at one point, everything will be so far from each other? So how is everything going to be ripped apart?
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