There are several information's already given in the question. Based on those information's the answer can be easily deduced.
Distance traveled by the bicycle rider = 50 km
Time taken to travel the distance = 2.5 hours
So
In 2.5 hours the bicycle rider travels = 50 km
Then
In 1 hour the bicycle rider travels = 50/2.5
= 20 km
Then the average speed of the cyclist is 20 km per hour.
Answer:
The angle of incidence is equal to the angle of reflection.
Explanation:
angle of incidence (i) = angle of reflection (r)
So if the angle of incidence was 45°, the angle of reflection would also be 45°.
Answer:
d. Relative humidity increases.
Explanation:
The expression of relative humidity in terms of absolute humidity, absolute pressure and saturation pression at measured temperature is:

When temperature decreases, the saturation pressure decreases also and, consequently, relative humidity increases. Therefore, the right answer is option D.
Quasar is famous for being an intergalactic object which is billions of years away from the earth yet can still be seen, unlike the other star body, unlike giant galaxies.
Hence, the fact that quasars can be detected from distances where even the biggest and most luminous galaxies cannot be seen means that "they must be intrinsically far more luminous than the brightest galaxies."
This condition, including other related evidence gotten in recent years concerning our galaxy, has shown that quasars are probably the central nuclei of very distant, very active galaxies.
The surprising thing was that quasars and active galaxies have a lot of mass in the center of the very small volume of the space.
Therefore, the surprising thing about quasars was that due to this mass and energy they are 100 times more luminous than Milky Way which means they have high recession velocity and a very large amount of red-shifting.
To learn more about quasars, refer: brainly.com/question/9965257
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