Snell's Law illustrates the relationship between the angles of incidence and refraction for a wave intruding on an interface between two medium with different indices of refraction. Snell's law is also known as the Snell-Descartes law and the law of refraction.
n1 = Refractive Index of first medium n2 = Refractive Index of second medium sinθ1 = Angle of Incidence sinθ2 = Angle of Refraction
n1 = 5,n2 = 9,θ1 = 50,
Angle of refraction(θ2)
Substitute the values of n1, n2 and θ1 in the formula, 5 x sin 50 = 9 x sinθ2
Take sin θ2 to L.H.S and the other values to R.H.S sin θ2 = 5 x sin50 / 9 Substitute the value of sin50 = 0.7660 sin θ2 = 5 x 0.7660 / 9 sin θ2 = 3.83022215 / 9 sin θ2 = 0.425580246
Now, bring θ2 to L.H.S θ2 = sin-1 (0.425580246) Therefore, θ2 = 25.1858 Hence, Angle Of Refraction θ2 = 25.1858
Learn how to calculate the Refractive Index and Angle Of Incidence in this tutorial which is given with the definition, formula and example.