In some cases, a supernova in a binary system may lead to the eventual formation of an accretion disk around the remains of the star that exploded. All of the following statements about such accretion disks are true except
A) X-rays are emitted by the hot gas in the accretion disk.
B) the accretion disk consists of material that spills off the companion star.
C) the central object about which the accretion disk swirls may be either a neutron star or a black hole.
D) several examples of flattened accretion disks being "fed" by a large companion star can be seen clearly in photos from the Hubble Space Telescope.
E) the radiation from an accretion disk may vary rapidly in time.
D
You might also like to view...
The present motions of the planets were inherited from the rotation of the solar nebula
a. True b. False Indicate whether the statement is true or false
Spheres of Charge: In the figure, a conducting sphere of radius r1 = 0.050 m is placed at the center of a spherical conducting shell of inner radius r2 = 0.100 m and outer radius r3 = 0.140 m. The inner sphere carries an excess charge of -4.0 nC. The outer spherical shell carries a net excess charge of 3.0 nC. Calculate the magnitude of the electric field at the following distances r from the center of the spheres. (k = 1/4??0 = 9.0 × 109 N ? m2/C2) (a) r = 0.075 m (in the air space between spheres),(b) r = 0.120 m (in the metal of the spherical shell), and(c) r = 0.200 m (outside the spherical shell).
What will be an ideal response?
As viewed by us here on Earth, where does time run slowest?
A) the surface of a white dwarf B) the surface of the Sun C) the surface of the Earth D) the top of Mount Everest on Earth E) in empty space
A Boeing 737 airliner has a mass of 20,000 kg and the total area of both wings (top or bottom) is 100 m2 . What is the pressure difference between the top and bottom surface of each wing when the airplane is in flight at a constant altitude?
a. 1960 N/m2 b. 3920 N/m2 c. 7840 N/m2 d. 4560 N/m2 e. 3070 N/m2