Darker is warmer C. Black objects.
<span>C. It is the difference in electrical potential energy between two places in an electric field.</span>
Answer:

Explanation:
Given that,
The speed of an electromagnetic wave traveling in a transparent nonmagnetic substance is given by :

Where
k is the dielectric constant of the substance.
v is the speed of light in water


So, the speed of light in water is 
Elements is the answer to this question
A 5kg backpack will weigh 49 newtons on earth