Answer:
false. it's positive terminal of an electric cell
Answer:
F= 1800N
Explanation:
the equation for force is F= ma
so plug in the numbers: F= (120)(15)
solve this to get F= 1800N
tip: don't forget to add the units when writing your answer :)
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:
1917723.40119 m/s
Explanation:
m = Mass of deuteron = 
k = Boltzmann constant = 
T = Temperature = 
RMS velocity is given by

The RMS velocity of the deutrons is 1917723.40119 m/s