12.4 • (a) What is the average density of the sun? (b) What is the av- erage density of a neutron star that has the same mass as the sun but a radius of only 20.0 km?

a) b) Electron degeneracy pressure in a white dwarf star, of uniform density p, in the nonrela- tivistic case is given by Pwd ħ² 3memp 25/305/3 where symbols have their usual meanings. Using the result that the central pressure in a star, of radius R and uniform density, under gravitational attraction is given by Pc = Gp² R², derive an expression for the radius Rwd of a white dwarf in terms of its mass M, in the case of nonrelativistic electron degeneracy. Using your result, briefly discuss the limitations of your expression for the radius, in the context of white dwarfs of increasing mass. Consider a white dwarf, mass M, radius Rwd and temperature T, consisting entirely of helium nuclei and electrons. Show that the internal thermal energy of the ions alone is given by 3 M Eth= -kT, 8 mp where mp is the proton mass. White dwarfs initially have a very high temperature when they form, and then cool by radi- ation. Derive a differential equation for the rate of change of the temperature…

a)Define the term “standard candle” as used in cosmology.  b)The flux is defined asf(Dlum) = L/4πD^2lumwhere L is the absolute luminosity and Dlum is the distance to the radiation source (youmay assume z ≪ 1).Assume that we have measured the flux to be f = 7.234 10^−23 Wm^−2 and the absoluteluminosity is given by L = 3.828 x10^26W. Calculate the luminosity distance D lum to the objectin Mpc.

Of 1.5, 3, 5, and 10 give the maximum apparent speeds. 2. Consider a relativistic jet with an angle of 70 degrees relative to the line of sight (i.e. it is almost, but not quite perpendicular to the line of sight). Let its value of gamma for the motion be 3. (a) Will it appear superluminal? (b) Will it appear to be brighter or fainter than it would in its own rest frame? 3. State whether the following reactions are possible under special relativity. If not, explain

Scientists are conducting an experiment to determine if their hypothesis that a certain constant in the universe is 1.65. the uncertainties in the experiment result in a relative uncertainty of no more than 2%. After several experimental trials, the scientists obtained an average value of 1.7 for the constant. What can be said about the scientists hypothesis? Hint calculate the percent error and compare it to the relative uncertainty.

What is this equation equal to: = ? E ijk klm mni Inspecting the equation above, what is its rank? Note: You can form any proofs you want (based on permutation, or based on its relation to the Kronecker delta).

Refer to this table to determine the average distance between the Earth and the Sun. Then calculate the average speed of the Earth in its orbit in kilometers per second and meters per second?

QUESTION 10 In Exercise 12.4 of your book, University Physics 15th edition (see End of the Chapter 12 section), what is the answer for sub-item (b) if the radius of the neutron star is 10.408 km? (express your answer in the proper SI unit and without scientific notation)

Schrodinger's cat is one of the most common subjects in modern physics for cartoonists. Here's what Erwin Schrodinger said about his famous thought experiment, "One can even set up quite ridiculous cases. A cat is penned up in a steel chamber, along with the following diabolical device (which must be secured against direct interference by the cat): In a Geiger counter, there is a tiny bit of radioactive substance, so small that perhaps in the course of one hour, one of the atoms decays, but also, with equal probability, perhaps none; if it happens, the counter tube discharges, and through a relay releases a hammer which shatters a small flask of hydrocyanic acid. If one has left this entire system to itself for an hour, one would say that the cat still lives if, meanwhile, no atom has decayed. The first atomic decay would have poisoned it. The function of the entire system would express this by having in it the living and dead cat (pardon the expression) mixed or smeared out in equal…

High energy cosmic rays from space hit the nitrogen in the atmosphereand convert it from nitrogen (N14) into carbon (C14). This produces a steadyconcentration of C14 in the atmosphere once the decay rate of the C14 back intoN14 matches the conversion rate from the cosmic ray flux (which is assumedto be constant for reasons you can ask me about if you want).a) What kind of radiation (what kind of particle) does the C14 emit when it decays? Tellme how you know?b) The concentration of C14 in plants (and animals) comes into equilibrium with the atmosphere because living things use the ambient carbon to make their cellular structures.However, once a plant dies, it no longer consumes C14. The C14 starts to decay away—allowing us to calculate when the plant died because the C14/C12 ratio doesn’t match theatmosphere. If the half life of C14 is 5000 years, what is the age of a piece of charcoal froma site from the Clovis peoples of North America if the concentration of C14 is 15% of…