The answer is d that might help you
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.
Answer:
the Hudson Bay was covered with alpine glaciers
Explanation:
During the last glacial period, large portions of North America were covered with ice. The majority of the ice was from the ice sheets that were covering Canada and the northern part of the United States, and the alpine glaciers on the mountain ranges. Hudson Bay was all frozen at this point of time. It was not covered with alpine glaciers though, instead it was covered with the ice of the extended ice sheets, with the ice cover reaching up to 2 km in thickness.
answer: derived physical quantities are those quantities that are obtained from the basic physical quantities by multiplication or division and area is one of them