A. 
The orbital speed of the clumps of matter around the black hole is equal to the ratio between the circumference of the orbit and the period of revolution:
where we have:
is the orbital speed
r is the orbital radius
is the orbital period
Solving for r, we find the distance of the clumps of matter from the centre of the black hole:
B. 
The gravitational force between the black hole and the clumps of matter provides the centripetal force that keeps the matter in circular motion:
where
m is the mass of the clumps of matter
G is the gravitational constant
M is the mass of the black hole
Solving the formula for M, we find the mass of the black hole:
and considering the value of the solar mass
the mass of the black hole as a multiple of our sun's mass is
C. 
The radius of the event horizon is equal to the Schwarzschild radius of the black hole, which is given by
where M is the mass of the black hole and c is the speed of light.
Substituting numbers into the formula, we find
Answer:
3050.6 Litre .
Explanation:
Total time of heart beat = Total time of race = 2 hrs , 39 minutes and 54 seconds
= 2 x 60 + 39 + 54/60 min
= 120 + 39 + .9 min
= 159.9 min
rate of heart beat = 170 per min
Total no of heart beat during race = 170 x 159.9
volume of blood per kg per beat = 2.5 mL per kg of weight
body weight = 99 pounds = .4535 x 99 kg = 44.89 kg
volume of blood per beat = 2.5 mL x 44.89 mL
= 112.225 mL .
Total required volume of blood = 112.225 x 170 x 159.9 mL
= 3050612 mL
= 3050.6 L.
I believe the correct answer is C all the other options seem funny to me
Answer: The correct statements are:
- The atoms are very attracted to one another.
- The atoms are held tightly together.
Explanation:
Solid state: In this state, the molecules are closely packed and cannot move freely from one place to another that means no space between them and the intermolecular force of attraction between the molecules are strong.
In solid substance, the particles are very close to each other due to this the intermolecular forces of attraction are strongest.
The key point about solid are:
- The atoms are very attracted to one another.
- The atoms are not moving freely.
- It will not spread out evenly to fill any container.
- The atoms are held tightly together.
- The forces of attraction are strong to bring molecules together.
- The atoms are close and in fixed positions.
Answer:
its false
Explanation:
because if an leaf floats down from a tree it is not considered an object for a free-fall
