Answer:
b. less than w.
Explanation:
In this question, the application of length contraction is what helps us come to our conclusion. When an object moves very fast (relative to the observer), the length of the object seems to be smaller than it actually is (again, for the observer).
This is supported by the length contraction equation below:
L = 
Here, L is the observed length
is the original length of the object
v is the relative speed between the object and the observer
and c is the speed of light
Using this equation, we can see that as the speed between the object and the observer is increased to be close to that of light, the square root in the equation gives us values less than 1.0
This effectively decreases the length that is observed.
Answer:
1) Used in optical instruments such as telescopes.
2) Used to form mirages
Explanation:
1) Perhaps the simplest example of this is the astronomical refractor telescope with a right-angle eyepiece holder. Astro scopes mostly point at things high in the sky, but it is inconvenient to place your eye low to look up through the scope, so the light path is bent 90 degrees just before the eyepiece. This can be done with a mirror, but using a simple 45 degree prism (internal angles 45, 45, and 90 degrees) will do the 90 degree bend more efficiently.
2) So when a light pass from cold air to hot air light tends to bend from its path which is known as refraction. As the light get refracted it reaches to a point where the light tends to form 90 degree angle.
The four inner planets, those closest to the Sun, are Mercury, Venus, Earth, and Mars. They are smaller and composed mainly of metals and rocks. The four outer planets — Jupiter, Saturn, Uranus, and Neptune — are larger and composed mostly of gases.
Answer:
Temperature at the bottom will be 19.18°C
Explanation:
We have given height h = 807 m
Temperature at the top 
Specific heat of water c = 4200 
From energy conservation
Kinetic energy at the bottom = potential energy at the top
So 
So temperature at the bottom = 17.3+1.88 = 19.18°C
