Answer: From space/ astronauts
Explanation:
A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying.
Because no light can get out, people can't see black holes. They are invisible. Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently than other stars.
Answer:

Explanation:
The process during which pressure remains constant is called an isobaric process.
10 joules of work is done by the object
Answer:
6
Explanation:
The magnetic field inside a solenoid is given by the following formula:

where,
B = Magnetic Field Inside Solenoid
μ₀ = permittivity of free space
n = No. of turns per unit length
I = Current Passing through Solenoid
For Solenoid 1:

For Solenoid 2:
n₂ = 6n₁
Therefore,

Diving equation 1 and equation 2:

Hence, the correct option is:
<u>6</u>
Answer:
The difference between the two is, well for one
Spectrum: The entire range that the "waves" could be such, as visible light, x-ray's and so on.
Waves: These are different because they aren't telling you or showing the entire spectrum just which they length that they are.
It may confuse you but it makes sense to me (Sorry)
Explanation: