jpatel10989

Why are there no quasars relatively near to our galaxy?

a. Quasars are apparently an early stage in the evolution of some galaxies. Therefore we must look far away (deep into the past) in order to see evidence of them.

b. Quasars are characterized by very large redshifts. There may, in fact, be relatively nearby quasars. But these would not show such large redshifts, and we might not recognize them as quasars.

c. Quasars are extremely powerful sources of radiation. If there were a nearby quasar, its radiation would have prevented the formation of life on Earth. Thus, life can form only on planets not too close to a quasar.

To determine the distance to a remote galaxy, astronomers look for a standard candle—an object, such as a star, that lies within that galaxy and for which we know the luminosity (or, equivalently, the absolute magnitude). Which of these standard candles can be used to determine the distance to a typical quasar? (Select all that apply.)

a. RR Lyrae variables

b. Cepheid variables

c. Type Ia supernovae

d. none of them

How would you distinguish between thermal and non-thermal radiation such as the synchrotron radiation?

A.The spectrum of thermal radiation is the blackbody spectrum. The spectrum of non-thermal radiation is different. In the case of synchrotron radiation the spectrum decreases steadily with increasing frequency.

B.The spectrum of radiation from a thermal source increases steadily with increasing frequency. The spectrum of radiation from a non-thermal source, like synchrotron radiation, decreases steadily with increasing frequency.

C. The spectrum of thermal radiation is the blackbody spectrum. The spectrum of non-thermal radiation is different. In the case of synchrotron radiation the spectrum decreases steadily with increasing wavelength.

How does the unified model of active galaxies suggest that quasars, blazars, and radio galaxies are the same kind of objects viewed from different angles?

A.The unified model of active galactic nuclei defines a structure that viewed from different directions has the observed characteristics of quasars, blazars, or double radio sources.

B. If the jets are along the line of sight, it is seen as a quasar. If the jets are perpendicular to the line of sight, it is seen as a blazar. If it is viewed from some angle in between, we see a double radio source. The unified model of active galactic nuclei defines a structure that viewed from different directions has the observed characteristics of quasars, blazars, or double radio sources. If the jets are along the line of sight, it is seen as a double radio source. If the jets are perpendicular to the line of sight, it is seen as a quasar. If it is viewed from some angle in between, we see a blazar.

C.The unified model of active galactic nuclei defines a structure that viewed from different directions has the observed characteristics of quasars, blazars, or double radio sources. If the jets are along the line of sight, it is seen as a blazar. If the jets are perpendicular to the line of sight, it is seen as a double radio source. If it is viewed from some angle in between, we see a quasar.

Why were some astronomers skeptical that the redshifts of quasars gave a true indication of their distance?

A.There are three different types of redshifts: those caused by the Doppler effect, those caused by gravitational attraction, and those associated with the Hubble flow. It was believed that the large redshifts seen in quasars were not caused by the Hubble flow, but by a combination of the other two.

B. Accepting these distances would mean accepting the tremendous energy output required to make quasars visible at those distances. These were orders of magnitude more luminous than any other known energy source.

C.It was believed that bridges of material could be seen between some quasars and objects within the Milky Way. This suggested that quasars were much closer than their redshifts indicated.

2,3-dimethylbuta-1,3-diene and (z)-pent-3-en-2-one reacts with heat to give you what structure

1,2-dihydronaphthalene reacts with Br2/CCl4 dark 0 degrees to give what product

cyclohexa-1,3-diene reacts with 1 equiv HCl/CHCl3 to give what product

(a) Open the editor below and draw the skeletal structure for the indicated major organic product produced from the reaction below

4-methylpenta-1,3-diene reacts with HBr to give the kinetic product

what is that product

Open the editor below and draw the skeletal structure of the major organic product A resulting from the first reaction.

Open the editor below and draw the skeletal structure of the major organic product B resulting from the second reaction in the link below.

http://i18.photobucket.com/albums/b107/xshortiij/2...

(a) Draw the skeletal structure of the alcohol with the most number of carbons.

(b) Draw the skeletal structure of the desired ether.

Two other ethers will also be produced.

(c) Draw the skeletal structure of the undesired ether with the most number of carbons.

Two elimination products will also need to separated out of the product mixture.

(d) Draw the skeletal structure of the undesired elimination product with the most number of carbons.

A. Draw the skeletal structure of the alcohol with the least number of carbons.

B. Draw the skeletal structure of the desired ether.

Two other ethers will also be produced.

C. Draw the skeletal structure of the undesired ether with the least number of carbons.

wo elimination products will also need to separated out of the product mixture.

D. Draw the skeletal structure of the undesired elimination product with the least number of carbons

A fence 2 feet tall runs parallel to a tall building at a distance of 3 feet from the building. What is the length of the shortest ladder that will reach from the ground over the fence to the wall of the building?

A baton twirler throws a spinning baton directly upward. As it goes up and returns to the twirler's hand, the baton turns through five revolutions. Ignoring air resistance and assuming that the average angular speed of the baton is 1.70 rev/s, determine the height to which the center of the baton travels above the point of release

Air is being pumped into a spherical balloon so that its volume increases at a rate of 100 \mbox{cm}^3\mbox{/s}. How fast is the surface area of the balloon increasing when its radius is 18 \mbox{cm}? Recall that a ball of radius r has volume \displaystyle V=\frac{4}{3}\pi r^3 and surface area S=4\pi r^2.

When air expands adiabatically (without gaining or losing heat), its pressure P and volume V are related by the equation PV^{1.4}=C where C is a constant. Suppose that at a certain instant the volume is 700 cubic centimeters and the pressure is 77 kPa and is decreasing at a rate of 7 kPa/minute. At what rate in cubic centimeters per minute is the volume increasing at this instant

( y ) / ( x + 9y) = x^4 -3

at point (1 , -2/19)

where s is measured in feet and t in seconds

a . find the velocity in ft/sec of the particle at t = 0

b. the particle stops moving (i.e is in a rest) twice, once when t = a and once when t = b where A<B..

A =

B =

c. what is the position of the particle at time 10

d. what i the TOTAL distance the particle travels between time 0 and time 10?

Use this to find the equation of the tangent line to the parabola y = 4x^2 -4x + 2 at the point (2,10) . The equation of this tangent line can be written in the form where

m=?

b=?

let f(x) = 2x + 6 - 15e^x Then the equation of the tangent line to the graph of f(x) at point (0,-9) given by y=mx + b

m = ?

b=?