The mass of a neutron star is 2 times the mass of the Sun. What is the mass of the neutron star in kg? Give the answer to two significant figures. Remember you can enter 2.0 x 1030 as 2.Oe30.

I attempted to answer this question and I'm not sure what I am doing wrong. My formula says A.S. = 206265 (separation/distance from observer) I know to convert to the same units, so I ended up with 80 Million Km being 8 x 10 ^ -6 LY Could you please explain each step especially for the part that I got wrong for both A and B?

Calculate the number of miles in a light-year, using 1.86  105 mi/s as the speed of light. (Hint: The number of seconds in a year, 365 days, will be useful.) Answer in mi/y

The star Alpha Centauri is 4.367 light vears from earth. What velocity do you need to travel at to reach this star in 1,447 years. Give your answer as a fraction of the speed of light (e.g. 0.406 for 0.406c) Round your answer to 3 decimal places. Add your answer Question 8 An electron is accelerated accross a voltage of 344kV. What is the momentuum of the electron? Use a value for the electron masss of 511 kevic. Give your answer in units of keWc (eg if the answer is 350 kevic write 350I Round your answer to 0 decimal places. Add your answer

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?

A main sequence star of mass 25 M⊙has a luminosity of approximately 80,000 L⊙. a. At what rate DOES MASS VANISH as H is fused to He in the star’s core? Note: When we say “mass vanish '' what we really mean is “gets converted into energy and leaves the star as light”. Note: approximate answer: 3.55 E14 kg/s b. At what rate is H converted into He? To do this you need to take into account that for every kg of hydrogen burned, only 0.7% gets converted into energy while the rest turns into helium. Approximate answer = 5E16 kg/s c. Assuming that only the 10% of the star’s mass in the central regions will get hot enough for fusion, calculate the main sequence lifetime of the star. Put your answer in years, and compare it to the lifetime of the Sun. It should be much, much shorter. Approximate answer: 30 million years.

In 1999, scientists discovered a new class of black holes with masses 100 to 10,000 times the mass of our sun that occupy less space than our moon. Suppose that one of these black holes has a mass of 1x10^3 suns and a radius equal to one-half the radius of our moon. What is the density of the black hole in g/cm^3? The radius of our sun is 7.0x10^5 km, and it has an average density of 1.4x10^3 kg/m^3. The diameter of the moon is 2.16x10^3 miles.

Time left 1:45:56 A star has initially a radius of 680000000 m and a period of rotation about its axis of 33 days. Eventually it changes into a neutron star with a radius of only 45000 m and a period of 0.3 s. Assuming that the mass has not changed, find Assume a star has the shape of a sphere. (Suggestion: do it with formula first, then put the numbers in) [Recommended time : 5-8 minutes] (a) the ratio of initial to final angular momentum (Li/Lf) Oa. 2.17E+15 Ob. 24 Oc. 0.0416 Od. 4.61E-16 (b) the ratio of initial to final kinetic energy Oa. 4.85E-23 Ob. 396000 Oc. 2.53E-6 Od. 2.06E+22

What is the average density of a neutron star that has the same mass as the sun but a radius of only 20.0 km if the radius of the neutron star is 57.999 km?

(Astronomy) PSR1913+16 Problem I. Are the two stars in PSR 1913+16 pulsars, neutron stars, or a combination of the two?