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Answer: Infrared light</h2>
A dark nebula is a cloud of dust and cold gas, which does not emit visible light and hides the stars it contains.
These types of nebulae are composed mainly of the hydrogen they obtain from nearby stars, which is their fuel.
It is using infrared light that we can "observe" and analyze in detail what happens in the inner parts of these nebulae.
I don't know I guess its the plate tectonics
If one of two interacting charges is doubled, the force between the charges will double.
Explanation:
The force between two charges is given by Coulomb's law
K=constant= 9 x 10⁹ N m²/C²
q1= charge on first particle
q2= charge on second particle
r= distance between the two charges
Now if the first charge is doubled,
we get 
F'= 2 F
Thus the force gets doubled.
Answer:
Pitcher is accelerating the ball at 30 times of acceleration due to gravity = 294 m/s²
Explanation:
Force applied on baseball = 30 times weight of the ball.
Weight of ball = mg, where m is the mass of ball and g is acceleration due to gravity value.
We have force applied is also equal to product of mass and acceleration.
F = ma = 30 x mg
a = 30g
So, pitcher is accelerating the ball at 30 times of acceleration due to gravity = 294 m/s²
