27.5 because of you divide the 55miles with the time you get your velocity which is the speed.
To develop this problem it is necessary to apply the concepts related to the Dopler effect.
The equation is defined by

Where
= Approaching velocities
= Receding velocities
c = Speed of sound
v = Emitter speed
And

Therefore using the values given we can find the velocity through,


Assuming the ratio above, we can use any f_h and f_i with the ratio 2.4 to 1


Therefore the cars goes to 145.3m/s
Answer:
33.61°
Explanation:
Refractive index is equal to velocity of the light 'c' in empty space divided by the velocity 'v' in the substance.
Or ,
n = c/v.
v is the velocity in the medium (2.3 × 10⁸ m/s)
c is the speed of light in air = 3.0 × 10⁸ m/s
So,
n = 3.0 × 10⁸ / 2.3 × 10⁸
n = 1.31
Using Snell's law as:
Where,
is the angle of incidence ( 25.0° )
is the angle of refraction ( ? )
is the refractive index of the refraction medium (air, n=1)
is the refractive index of the incidence medium (glass, n=1.31)
Hence,
Angle of refraction =
= 33.61°