Answer:
B, C and D are true.
<h3>Explanation:</h3>
A is false because they appear a pale reddish colour not purple.
The speed of light in vacuum is exactly
299,792,458 meters per second.
That's so exact that it's the official scientific definition of a "meter".
The number doesn't t change even if the flashlight or other light source is moving.
Answer:
heliocentric is when the earth and the other planets revolves around the sun.
Explanation:
I'm not sure about which one but I do know what heliocentric is.
Answer:
54.6°
Explanation:
From law of reflection i=r.
So, construct the reflected ray at 55.7°degrees from the normal and let it fall on the other mirror.
Now draw the second normal at the point of incidence and again measure the angle of incidence, and draw the angle of reflection.
If you consider triangle AOB, one angle is ∠AOB=90°
and ∠OAB is 54.6°
From angle sum property third angle ie ∠ABO=180°-90°-54.6°=35.4°
So, the second incident angle will be 54.6°
Hence, the second reflected angle will be 54.6 degrees.