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.
Gases do not conduct heat well.
Answer:
Visible light
Explanation:
Electromagnetic spectrum is the classification of the electromagnetic waves according to their frequency/wavelength. In order from the shortest to the longest wavelength, we have
Gamma rays
X-rays
Ultraviolet
Visible light
Infrared
Microwaves
Radio waves
All these waves are invisible to human eye, except for the part referred as 'visible light'. The electromagnetic waves of this part of the spectrum are visible to human eye, and they appear as a different color depending on their wavelength. In particular, we have:
Violet: 380-450 nm
Blue: 450-495 nm
Green: 495-570 nm
Yellow: 570-590 nm
Orange: 590-620 nm
Red: 620-750 nm
Kinetic energy is the energy possessed by an object on motion. it is expressed as follows:
KE = 0.5mv^2
where m is the mass and v is the velocity of the object. We calculate as follows:
KE = 0.5mv^2
1.1x10^9 J = 0.5(8.0x10^4 kg) v^2
v = 165.83 m/s
After plugging all the data into the equation, the result of the relative centrifugal force (RCF) is measured in terms of g.
<h3>What is relative centrifugal force?</h3>
The relative centrifugal force (RCF) or the g force is the radial force generated by the spinning rotor as expressed relative to the earth's gravitational force.
RCF = ac/g
where;
- ac is centripetal acceleration
- g is acceleration due to gravity

where;
<h3>For example, </h3>
Find the maximum RCF of the JS-4.2 rotor can be obtained from its maximum speed (4200 rpm) and its rmax (250 mm);

Thus, after plugging all the data into the equation, the result is measured in terms of g.
Learn more about relative centrifugal force here: brainly.com/question/26887699
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