A question to think about on units: Suppose we wanted to exchange scientific information with a newly discovered species of intelligent life living on a planet orbiting the star Alpha Centauri. And suppose that our new friends have managed to become fluent in our language, but have not yet had the opportunity to visit the Earth. Which of the following statements would they understand? a. The mass of the electron is 9.10938188 x 10^-31.
b. The speed of light is 2.99792458 x 10^8 meters/second.
c. The ratio of the proton's mass to the electron's mass is 1836.153. Explain your reasoning

b. The speed of light is 2.99792458 x 10^8 meters/second.

Explanation:

Speed of light is a universal constant and its value is same throughout the universe . So alien living near Alpha Centauri will quickly understand about it . But other statements are not universal . Mass of electron can vary  as per relativistic formula of Einstein . Similarly , mass of proton can also vary according to relativistic concept . It depends upon the velocity of particle . So, the ratio of mass of proton and mass of electron will also vary from one star to another .

answer: the correct answer id option(d).

explanation:

snell's law refraction:

the angle of refraction =

the angle of incidence =

refractive index of air = = 1

refractive index of glycerol = 1.47

from the given options, the most closest answer to 63.72° is 65° of option (d).