MR. SURRETTE VAN NUYS HIGH SCHOOL

CHAPTER 15: REFLECTION AND REFRACTION

WORKSHEET

[Equations: n = sinq1/sinq2, n1sinq1 = n2sinq2, n = c/v, sinqc = n2/n1, c = 3.00 x 108 m/s]

1. Light in air enters a diamond (n = 2.42) at an angle of incidence of 30.0o. What is the angle of refraction inside the diamond? [ANS: 11.9o]

2. An underwater scuba diver sees the sun at an apparent angle of 35.0o from the vertical. How far is the sun above the horizon? (n = 1.33) [ANS: 49.7o]

3. Dispersion occurs when:

(A) some materials bend light more than other materials

(B) a material slows down some wavelengths more than others

(C) a material changes some frequencies more than others

(D) light has different speeds in different materials

(E) a material changes the color or incoming light

4. If the velocity of light through an unknown liquid is measured at 1.85 x 108 m/s, what is the index of refraction of this liquid? [ANS: 1.62]

5. If the critical angle for internal reflection inside a certain transparent material is found to be 56.0o, what is the index of refraction of the material? (Air is outside the material). [ANS: 1.21]

6. Which of the following describes what will happen to a light ray incident on an air-to-glass boundary at less than the critical angle?

(A) total reflection

(B) total transmission

(C) total dispersion

(D) partial reflection and total transmission

(E ) partial reflection and partial transmission

7. A beam of light in air is incident at an angle of 35.0o to the surface of a rectangular block of clear plastic (n = 1.49). The light beam first passes through the block and re-emerges from the opposite side into air at what angle to the surface? [ANS: 35o]

8. A beam of light in air is incident on the surface of a rectangular block of clear plastic (n = 1.49). If the velocity of the beam before it enters the plastic is 3.00 x 108 m/s, what is its velocity after emerging from the block? [ANS: 3.00 x 108 m/s]

9. A ray of light in air is incident on an air-to-glass boundary at an angle of 41.5o with the normal. If the index of refraction of the glass is 1.47, what is the angle of the refracted ray within the glass with respect to the normal? [ANS: 26.8o]

10. A light in air is incident on an air-to-glass boundary at an angle of 45.0o and is refracted in the glass at angle of 30.0o with the normal. What is the index of refraction of the glass? [ANS: 1.41]

11. A laser beam, incident at 30 degrees onto the surface of a block of glass, is partially reflected and partially transmitted (with refraction) at the block’s upper surface. The index of refraction of the glass is 1.5.

11a. What is the speed of light in the glass expressed as a fraction of c? [ANS: 0.67 c]

11b. Is the angle of refraction greater than, less than, or equal to 30 degrees?

11c. Calculate the angle of refraction in degrees. [ANS: 19.5o]

11d. What is the angle the reflected beam makes with the normal?

12. A beam of light in water strikes a boundary with air. The index of refraction of water is 1.33.

12a. If the angle of incidence is 41 degrees what is the angle of refraction? [ANS: 60.8o]

12b. Calculate the critical angle for these rays. [ANS: 48.8o]

12c. If the angle of incidence is 61 degrees what happens to the light at the boundary?

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PHYSICS