Water (nwater = 1.33) is poured into a container
made of crown glass (nglass = 1.52). If a light
ray in the glass is incident on the glass-to-liquid
boundary and makes an angle of 35° with the
normal, what is the angle of the corresponding
refracted ray with respect to the normal?
(Round to the nearest tenth and include the
base unit symbol.)



Answer :

To solve the problem of finding the angle of refraction of light as it passes from crown glass to water, we will use Snell's Law, which states:

[tex]\[ n_1 \sin(\theta_1) = n_2 \sin(\theta_2) \][/tex]

where:
- [tex]\( n_1 \)[/tex] is the refractive index of the first medium (glass in this case, [tex]\( n_1 = 1.52 \)[/tex]).
- [tex]\( \theta_1 \)[/tex] is the angle of incidence in the first medium (35°).
- [tex]\( n_2 \)[/tex] is the refractive index of the second medium (water in this case, [tex]\( n_2 = 1.33 \)[/tex]).
- [tex]\( \theta_2 \)[/tex] is the angle of refraction in the second medium, which we need to find.

### Step-by-Step Solution:

1. Convert the Angle of Incidence to Radians:

[tex]\[ \theta_1 = 35^\circ \][/tex]
To convert degrees to radians, use the conversion factor:
[tex]\[ \theta_1 = 35^\circ \times \frac{\pi}{180^\circ} = \frac{35\pi}{180} \approx 0.6109 \text{ radians} \][/tex]

2. Apply Snell's Law:

[tex]\[ n_1 \sin(\theta_1) = n_2 \sin(\theta_2) \][/tex]
Substitute the known values into Snell's Law:
[tex]\[ 1.52 \sin(0.6109) = 1.33 \sin(\theta_2) \][/tex]

3. Calculate [tex]\( \sin(\theta_1) \)[/tex]:

Using the sine function:
[tex]\[ \sin(0.6109) \approx 0.5736 \][/tex]
So,
[tex]\[ 1.52 \times 0.5736 \approx 0.8719 \][/tex]
Thus, Snell's Law now looks like:
[tex]\[ 0.8719 = 1.33 \sin(\theta_2) \][/tex]

4. Solve for [tex]\( \sin(\theta_2) \)[/tex]:

[tex]\[ \sin(\theta_2) = \frac{0.8719}{1.33} \approx 0.6555 \][/tex]

5. Find [tex]\( \theta_2 \)[/tex] Using the Inverse Sine Function:

[tex]\[ \theta_2 = \arcsin(0.6555) \][/tex]
Using the arcsine function:
[tex]\[ \theta_2 \approx 40.91^\circ \][/tex]

6. Round to the Nearest Tenth:

[tex]\[ \theta_2 \approx 40.9^\circ \][/tex]

So, the angle of the corresponding refracted ray with respect to the normal is approximately [tex]\( 40.9^\circ \)[/tex].