Answer:
★The second law of refraction
The ratio of sine of angle of incidence to the sine of angle of refraction is a constant for a light of given colour and for a given pair of media. This law is also called Snell's law of refraction. If 'i' is the angle of incidence and 'r' is the angle of refraction then, Sin i/Sin r = constant
This constant value is called the refractive index of the second medium with respect to the first.
Answer:

Explanation:
As we know that the acceleration of a point on the rim of the disc is in two directions
1) tangential acceleration which is given as

2) Centripetal acceleration

here we know that


now we know that net linear acceleration is given as

so we have


The three main constructive forces are crustal deformation, volcanic eruptions, and deposition of sediment.
answer
option d is the correct answer
explanation
as we know frequency is equal to 1 /t
f= 457 Hz
t=1
SO, 1/457
=0.0022sev