Based on the information in the question, a light year is the distance traveled light in one year. Then if the light from the star Centauri takes 4.2 years to reach the earth, then its distance from earth is 4.2 light years.
The correct answer is
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force per unit charge.
In fact, the electric field strength is defined as the electric force per unit charge experienced by a positive test charge located in the electric field. In formula:
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where
E is the electric field strength
F is the electric force experienced by the charge
q is the positive test charge.
If you measured all the energy related to motion and all the stored
energy in the particles of a substance, you would be measuring the thermal energy of the particles. If
there is movement of the particles, they are also releasing energy in the form
of heat.
It is the same if a white father and a white mother give birth to a black kid, so the mother accuses the father for having (let's say mating) with a black women.