Answer:
The second material's index of refraction is 1.17.
Explanation:
Given that,
Refractive index of the material, n = 1.29
Critical angle is 65.9 degrees.
We need to find the second material's index of refraction. We know that at critical angle of incidence, angle of refraction is equal to 90 degrees. Using Snell's law as:

So, the second material's index of refraction is 1.17.
Answer:
total time =4.583 hour
Explanation:
We have given total distance = 60 mi
It is given that half of the distance traveled by a speed of 8 mph
We know that 
And second half of the distance traveled by a speed of 36 mph
So time 
So total time = 3.75 + 0.833 =4.583 hour
Try B if it is not it I am sorry I checked on Google
Answer:
The environments in which cells grow often change rapidly.
Explanation: