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 magnitude of electron acceleration is

Explanation:
Given:
Distance from the wire to the field point
m
Speed of electron 
Current
A
For finding the acceleration,
First find the magnetic field due to wire,

Where 

T
The magnetic force exerted on the electron passing through straight wire,

N
From the newton's second law

Where
mass of electron
kg
So acceleration is given by,



Therefore, the magnitude of electron acceleration is

Answer: As the temperature of the water decreases from 20 degrees celsius to 4 degrees celsius, the density increases.
Explanation:
Answer:
The power in this flow is 
Explanation:
Given that,
Distance = 221 m
Power output = 680 MW
Height =150 m
Average flow rate = 650 m³/s
Suppose we need to calculate the power in this flow in watt
We need to calculate the pressure
Using formula of pressure

Where,
= density
h = height
g = acceleration due to gravity
Put the value into the formula


We need to calculate the power
Using formula of power

Put the value into the formula


Hence, The power in this flow is 
Answer:
B. Thermal energy
E. Sound energy
Explanation:
Thermal and sound energy is kinetic energy.
Kinetic energy is the energy that results as a function of the motion of a body or the particles of the medium.
Sound energy is transmitted by the vibration of the particles in the air. The vibration leads to movement of the particles and hence, kinetic energy is produced.
Thermal energy originates as a result of the temperature differences in a body. This temperature difference leads to the increase in the kinetic energy of some particles which also causes vibration and motion of the particles.