# The figure below shows a refracted light beam in oil making an angle of α = 17.5° with the normal line NN'. The index of refraction of the oil is 1.46.

The figure below shows a refracted light beam in oil making an angle of α = 17.5° with the normal line NN'. The index of refraction of the oil is 1.46.

(a) Determine the angle θ.
°

(b) Determine the angle θ'.
°
asked Apr 2, 2012 in Physics

Apply Snell's law of relfection, which states that:

n1*sin(theta1) = n2*sin(theta2)

(*where n1 and n2 = indices of refraction of the two media)

n1 = 1  (indices of refraction of air, )

n2 = 1.46 (indices of refraction of oil )

theta1 = the angle of incidence in air

theta2 =  the angle of incidence in oil = 17.5 degrees

plugging these back into the formula you can solve for theta1

Part B is more or less the same thing.

Only this time you know theta1, which is the angle of incidence in oil, and you are instead solving for the angle of incidence in water

n1*sin(theta1) = n2*sin(theta2)

n1 = 1.46  (indices of refraction of oil)

n2 = 1.33 (indices of refraction of water )

theta1 = the angle of incidence in oil =17.5 degrees

theta2 =  the angle of incidence in water

so pluggin these values into the formula solve for theta2

answered Apr 3, 2012 by ~Expert~ (3,020 points)
selected Apr 9, 2012 by Gummmys