Answer:
Answer is It was deduced from the rate at which it glimmers.
Refer below.
Explanation:
The X-ray source Cygnus X-1 has a mass of at least 11 solar masses and a diameter of only about one-quarter the diameter of the Earth. With such a small diameter it must be a compact object, and with such a large mass it can't be a white dwarf or a neutron star, so a black hole is the only possibility remaining. The diameter of Cygnus X-1 found:
It was deduced from the rate at which it glimmers.
<h3>WATER</h3>
Explanation:
<h2>#CARRYINGTOLEARN:)</h2>
Here we will the speed of seagull which is v = 9 m/s
this is the speed of seagull when there is no effect of wind on it
now in part a)
if effect of wind is in opposite direction then it travels 6 km in 20 min
so the average speed is given by the ratio of total distance and total time


now since effect of wind is in opposite direction then we can say



Part b)
now if bird travels in the same direction of wind then we will have


now we can find the time to go back



Part c)
Total time of round trip when wind is present


now when there is no wind total time is given by


So due to wind time will be more