Answer:
The angle of incidence is 
Explanation:
The diagram for this question is shown on the first uploaded image
From the question we are told that
The distance between the mirror and the wall is 
The height of the above the mirror is 
Generally the angle which the reflected ray make with the mirror is mathematically evaluated as
substituting values
From the diagram we can deduce that the angle of incidence is
So 
Answer:
The Universe became transparent to the light left over from the Big Bang when it was roughly 380,000 years old
Explanation:
The three main parts of an atom are protons, neutrons<span>, and </span>electrons<span>. </span>Protons<span> - have a positive charge, located in the </span>nucleus<span>, </span>Protons<span> and </span>neutrons<span> have nearly the same mass while </span>electrons<span> are much less massive. </span>Neutrons<span>- Have a negative charge, located in the </span><span>nucleus</span>
Answer: to only change one factor in an experiment or test
