Answer:
<em>b. Observe the radio waves coming from all dark matter; from the strength of the radio waves from each cluster, estimate the amount of dark matter needed to produce them.</em>
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Explanation:
The universe is thought to be made up of 85% dark matters. <em>Dark matter is called dark because it does not appear to interact with the electromagnetic field, which means it doesn't absorb, reflect or emit electromagnetic radiation, and is therefore difficult to detect. This means that option b is wrong since radio wave is an electromagnetic wave</em>. Dark matter is a form of matter that makes up about a quarter of the total mass–energy density of the universe. Dark matter was theorized due a variety of astrophysical observations and gravitational effects that cannot be explained by accepted theories of gravity unless there were more matter in the universe than can be seen.
Answer:
Mass of the disk will be 2.976 kg
Explanation:
We have given force F = 45 N
Radius of the disk r = 0.12 m
Angular acceleration 
We know that torque 
And 
So
, here I is moment of inertia
So 

We know that moment of inertia 
So 
m = 2.976 kg
Explanation:
A projectile (Cannon ball) is launched at an angle to the horizontal and rises up to a peak while moving horizontally. When it reaches the peak, the projectile starts to fall.
Air expands as it warms. Therefore warm air is less dense than cool air. The warm air from the first floor apartments rises to the second floor. People on the second floor require less heating to keep their <span>apartments comfortable.
-Hope this helps </span>
<span>Like charges repel and opposite charges attract.
The further away two charged objects are the weaker the electrical force between them.
The closer two charged objects are the stronger the electrical force between them.
Hope this helps :)</span>