The mass density of our universe is measured to be about 10-29 kg/m3. If an arbitrary point is chosen as the center, how large is the radius of a spherical surface centered at the point so that the mass enclosed in the surface will become a blackhole observed by someone outside the surface? A. 4.2 trillion light years B. 420 billion light years C. 42 billion light years D. 4.2 billion light years

The mass density of our universe is measured to be about 10-29 kg/m3. If an arbitrary point is chosen as the center, how large is the radius of a spherical surface centered at the point so that the mass enclosed in the surface will become a blackhole observed by someone outside the surface? A. 4.2 trillion light years B. 420 billion light years C. 42 billion light years D. 4.2 billion light years

Physics for Scientists and Engineers with Modern Physics

10th Edition

ISBN:9781337553292

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter44: Particle Physics And Cosmology

Section: Chapter Questions

Problem 30P

See similar textbooks

Similar questions

The supermassive black hole at the center of a galaxy has a mass of 6.5 billion solar masses. If we assume that it is a Schwarzschild black hole, what is the radius of this black hole? A. 18 light hours B. 20 light hours C. 16 light hours D. 14 light hours Is the answer A? S. radius = 3 x 6.5 x 109 x 9.26567-10 = 18.1 light hours Thanks!
Based on what you have learned about galaxy formation from a protogalactic cloud (and similarly star formation from a protostellar cloud), the fact that dark matter in a galaxy is distributed over a much larger volume than luminous matter can be explained by I. Dark matter does not emit EM radiations. II. The pressure of an ideal gas decreases when temperature drops. III. The temperature of an ideal gas decreases when its thermal energy decreases. A. I only B. I and III only C. II and III only D. I, II and III Is the answer C? Thank you!
Astronomers use a light-year to measure distance. A light-year is the distance light travels in one year. The speed of light is approximately 300,000 km/sec.a. How long is 1 light-year in kilometers?b. The nearest star (other than the sun) is Alpha Centauri. It is 4.34 light-years from Earth. How far is that in kilometers?c. How long will it take a rocket traveling 42,000 km/hr to reach Alpha Centauri?
A light-year is the distance that light can travel in one year. Similarly, we can define a light-second, light-day, etc. as the distance that light can travel in other time intervals. Calculate the distance represented by each of the following: (Assume that the speed of light is 3 x 108 m/s)A. 4 light-seconds.B. [3pt] 4 light-minutes.C. 4 light-days.D. 4 light-days, but this time answer in miles (enter just the number with no units)
Early astronomers thought that galaxies were single stars. Why was this mistake easy to make? A. Galaxies are so far away that they look like a single star. B. Galaxies are made of stars that you can only see one at a time. C. Light from galaxies collects into a single beam. D. Earth is small and galaxies are much larger.
8. Milky Way The Sun is a star in the Milky Way galaxy. When viewed from the side, the galaxy looks like a disk that is approximately 100,000 light-years in diameter (a light-year is the distance light travels in one year) and about 1000 light-years thick (Figure P25.8). What is the diameter and thickness of the Milky Way in meters? In kilometers? In miles? Figure P25.8 Galactic Longitude 75.000 ittarius Sagitt Arm Onan Perseus Arm Arm 15,000 30.000 180° Scutum-Ce 270° Sun and solar system's location in the Milky Way
The flatness problems states that a. the density of the universe is very close to the critical density. b. the density of the universe is much larger than the critical density. c. the flat universe would expand forever and we could never measure the density of the universe. d. the laws of physics may not be different at different times in the history of the universe. e. the redshift of a distant galaxy is caused by the curvature of space-time.
What happens when galaxies collide? A. Star collisions will be rare but the shapes of the galaxies will be largely distorted. B. The shapes of the galaxies will be largely distorted and many of the stars of one galaxy will collide with stars of the other galaxy. C. The shapes of the galaxies will be distorted and many stars will collide with stars of the other galaxy, as well as with other stars in the same galaxy. D. Star collisions will be rare and the two galaxies will just pass through each other without any changes. Is the answer A? Thank you!
The red-shift of a galaxy observed by us corresponds to a speed of 50000 km/s. How far is the galaxy from us approximately? A. 700 Mpc B. 70 Mpc C. 7 Mpc D. 7 Gpc Is the answer A? Thank you!
Which of the following might you expect to be an additional consequence of the fact that galaxies contain more mass than expected?A. The gravitational force between galaxies is greater than expected.B. Galaxies appear less bright than expected.C. Galaxies are farther away than expected.D. There are more galaxies than expected.
The age of the universe can be determined if a. the universe is flat. b. the amount of dark matter in the universe can be accurately determined. c. the rate of recession of the galaxies in the Local Group can be accurately determined. d. the temperature of the cosmic background radiation can be accurately determined. e. the Hubble constant and density of the universe can be accurately determined.
We know that dark matter must exist in galaxies. If not, many of the stars in a galaxy would ... a.Expand and go supernova due to the expansion of the Universe b.Fly away from the galaxy because the stars’ velocities are so large, and the galaxy would not have enough gravity to hold onto them c.Orbit the center of the galaxy normally d.Spiral in toward the center of the galaxy because most of the galaxy’s mass would be toward the center