D. it is decreased by a factor of 9.
Force = kqq ÷ r^2
The distance is squared so if it is increased or decreased by any factor, then it must be squared too. Because the distance is on the bottom of the equation, you divide the force by the increasing or decreasing factor.
.
<h3>Explanation</h3>
The peak emission wavelength of an object depends on its absolute temperature.
,
where
is the wavelength in meters where the emission is the strongest.
is the temperature of the object in degrees Kelvins.
For the gas falling into the black hole,
.
Apply the formula:
.
The question mentioned that is in the X-ray region of the electromagnetic spectrum. According to Encyclopedia Britannica, the wavelength of X-rays range from 
to 
, which indeed includes 
.
The planets move eastward against the background of fixed stars with the exception of Venus, Uranus and Pluto moving westward as seen in Earth's sky . This apparent retreating movement is called Retrograde motion. It is illusion created by Earth's movement going by outer planets in their respective orbits.
Balancing.
When the same force is applied from both sides,the forces cancel out each other.
