The correct hierarchy would be
-<span>A solar system is a collection of planets, their moons, and other objects in orbit around a central star.
</span><span>-A galaxy refers to all existing matter, energy, and space that is held together by gravity</span>
The centripetal acceleration of an object is given by the relation,

where Ac = centripetal acceleration =
R = radius of rotation = 15 m
V = speed of astronaut
Hence, 
solving this we get, V = 38.34 m/s
I think It would be C. Checking a prediction. Sorry if I’m wrong
The equation that represents the principle of the lever balance is:
- W₁ + W₂ = W3 + W4; option A.
<h3>What is the principle of moments?</h3>
The principle of moments states when a body is in equilibrium, the sum of the clockwise moment about a point equals the sum of anticlockwise moment about that point.
A see-saw represents a balanced system of moments.
The sum of clockwise moment = The sum of anticlockwise moments.
Assuming W1 and W2 are clockwise moments and W3 and W4 are anticlockwise moments.
The equation will b: W₁ + W₂ = W3 + W4
In conclusion, a balanced see-saw illustrates the principle of the lever balance.
Learn more about principle of moments at: brainly.com/question/20519177
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