Yes there is an elastic collision in physics its when a collision occurs but no kinetic energy is loss. We study them in order to understand how to conserve momentum.
Y-STR analysis. It is a DNA test used to compute and match with the possibility via lap.
Answer:
n = 1.4266
Explanation:
Given that:
refractive index of crystalline slab n = 1.665
let refractive index of fluid is n.
angle of incidence θ₁ = 37.0°
Critical angle 

According to Snell's law of refraction:

At point P ; 

Therefore:

Then maximum value of refractive index n of the fluid is:


n = 1.4266