Answer:
is reflected back into the region of higher index
Explanation:
Total internal reflection is a phenomenon that occurs when all the light passing from a region of higher index of refraction to a region of lower index is reflected back into the region of higher index.
According to Snell's law, refraction of ligth is described by the equation

where
n1 is the refractive index of the first medium
n2 is the refractive index of the second medium
is the angle of incidence (in the first medium)
is the angle of refraction (in the second medium)
Let's now consider a situation in which

so light is moving from a medium with higher index to a medium with lower index. We can re-write the equation as

Where
is a number greater than 1. This means that above a certain value of the angle of incidence
, the term on the right can become greater than 1. So this would mean

But this is not possible (the sine cannot be larger than 1), so no refraction occurs in this case, and all the light is reflected back into the initial medium (total internal reflection). The value of the angle of incidence above which this phenomen occurs is called critical angle, and it is given by

No it's the opposite, ths higher the pitch the greater the frequency.
Hi!
1 decimeter = 100 millimeters.
Therefore 2 decimeters = 200 millimeters.
Answer:
48 m
Explanation:
Two trains traveling towards one another on a straight track are 300m apart when the engineers on both trains become aware of the impending Collision and hit their brakes. The eastbound train, initially moving at 97.0 km/h Slows down at 3.50ms^2. The westbound train, initially moving at 127 km/h slows down at 4.20 m/s^2.
The eastbound train
First convert km/h to m/s
(97 × 1000)/3600
97000/3600
26.944444 m/s
As the train is decelerating, final velocity V = 0 and acceleration a will be negative. Using third equation of motion
V^2 = U^2 - 2as
O = 26.944^2 - 2 × 3.5 S
726 = 7S
S = 726/7
S1 = 103.7 m
The westbound train
Convert km/h to m/s
(127×1000)/3600
127000/3600
35.2778 m/s
Using third equation of motion
V^2 = U^2 - 2as
0 = 35.2778^2 - 2 × 4.2 × S
1244.52 = 8.4S
S = 1244.52/8.4
S2 = 148.2 m
S1 + S2 = 103.7 + 148.2 = 251.86
The distance between them once they stop will be
300 - 251.86 = 48.14 m
Therefore, the distance between them once they stop is 48 metres approximately.