Refraction and Snell's law

Answer Key - Grade 11 Science Worksheet

Circle the best answer, or write your answer on the line.

1. 1.

   Use n = 1.00 for air. A ray in air enters water (n = 1.333) at 40° to the normal. At what angle to the normal does it travel inside, to 0.1°, Ari?

   28.8 °
2. 2.

   Use n = 1.00 for air. A ray in air enters Plexiglas (n = 1.49) at 30° to the normal. At what angle to the normal does it travel inside, to 0.1°, Bo?

   19.6 °
3. 3.

   Use n = 1.00 for air. A ray in air enters diamond (n = 2.417) at 60° to the normal. At what angle to the normal does it travel inside, to 0.1°, Esme?

   21 °
4. 4.

   A straw in a glass of water looks bent at the surface. What causes this, Jun?

   • The glass reflects the straw
   • Light bends as it leaves the water
   • The water bends the straw
5. 5.

   A coin at the bottom of a cup of water looks closer to the top than it is. Why, Kira?

   • Its light bends at the water's surface
   • Water makes the coin float up
   • The cup magnifies it
6. 6.

   In water, a ray travels at 28.8° to the normal toward the surface. At what angle to the normal does it leave into air, Milo?

   • 21.6°
   • 40°
   • 28.8°
7. 7.

   Use n = 1.00 for air. A ray inside water (n = 1.333) hits the surface at 30° to the normal. At about what angle does it leave, Noah?

   • 30°
   • About 41.8°
   • About 22.0°

8. Read this first

   Refractive indices (Engineering ToolBox)

   Material	Refractive index n
   air (0 °C)	1.00029
   ice	1.31
   water (20 °C)	1.333
   quartz glass	1.46
   Plexiglas	1.49
   diamond	2.417

9. 8.

   Using the table, about how many times as fast does light travel in water as in diamond, Ren?

   • About 0.55 times
   • About 1.81 times
   • About 3.75 times
10. 9.

    Using the table, rays from air enter each solid at the same angle. Which bends the ray most, Tala?

    • Diamond
    • Quartz glass
    • Ice
11. 10.

    Using the table, a ray passes from ice into water. How much does it bend, Zee?

    • It reflects back into the ice
    • Only a little, since their indices are close
    • A great deal, like air into diamond