Answer:
the orbits of the planets are elliptical
the sun is the center of the solar system
includes 9 planets
I'm not sure about the rest but for question 2:
A theory is an attempt to come up with a big picture of all we know so far. It also drives future research as people do experiments to see if what the theory predicts actually happens. When experiments don’t support the theory, you have to change the theory and try again. That’s how science works. We come up with a “best guess” (theory), and then do research to test it’s accuracy. As we discover contradictions, we adjust the theory to take those into account, and then start testing the validity of the new theory.
The correct answer is (A). The speed of light would increase to a speed larger than the maximum speed of light in vacuum.
The index of refraction is the ratio of speed of light in vacuum to the speed of light in a medium.
n=C/V
here, n is the index of refraction, c the speed of light in vacuum, v is speed of light in any medium.
Now if the value of index of refraction is less than one, than the value of speed of light would be greater than the speed of light in the vacuum.
It is important to note that the electromagnetic spectrum has a variety of wavelength and frequency of light in it. Some lights we can see, while others are not visual to our naked eye. It is actually very important to determine the kind of light as different lights have different wavelengths and frequencies. some lights are of very high frequency like the gamma rays, while others are of far lower frequency. <span />
