Answer:
Step-by-step explanation:
using Snell's law of refraction
n₁ sinθ₁ = n₂ sinθ₂
where n₁ = the indexes of refraction of the material with incident light
n₂ = the indexes of refraction of the material with refracted light
θ₁ = angle of incidence and θ₂ = angle of refraction
for red light
n₁ sinθ₁ = n₂ sinθ₂
1 × sin 58 = n₂ sin37.7
n₂ = ( 1 × sin 58) / sin 37.7° = 1.387 for red light
for violet light
n₁ sinθ₁ = n₂ sinθ₂
1 × sin 58 = n₂ sin36.7
n₂ = ( sin 58 ) / sin36.7 = 1.419 for violet light
the speed of red light can be calculated with formula below
n = c / v where c is the speed of light = 3 × 10 ⁸ m/s and v is the speed of the red light
v = c / v = (3 × 10 ⁸ ) / 1.387 = 2.163 ×10 ⁸ m/s
for violet light
v = ( 3 × 10 ⁸) / 1.419 = 2.11 × 10 ⁸ m/s