Let me work through this problem step by step.
Understanding the question:
The question asks what happens when light travels from a less dense medium to a more dense medium. This is about refraction - how light bends when it passes between different materials.
Key concept:
When light moves between materials with different densities (like from air to water, or from glass to diamond), it changes speed and direction. The "normal" is an imaginary line perpendicular (at 90 degrees) to the surface where the two materials meet.
What happens in each case:
1.
Less dense → More dense (like air to water):
- Light slows down
- The ray bends TOWARD the normal
- Example: When you look at a straw in a glass of water, it looks bent because light bends toward the normal as it goes from air into water
2.
More dense → Less dense (like water to air):
- Light speeds up
- The ray bends AWAY from the normal
3.
Same density or straight on:
- If light hits exactly perpendicular to the surface (along the normal), it continues straight even if densities are different
Analyzing the options:
- a. "bent away from the normal" - This happens when going from MORE dense to LESS dense, so this is wrong
- b. "continues in the same direction" - This only happens if light hits perpendicular to the surface OR if both media have the same density, so this is generally wrong
- c. "bent toward the normal" - YES! This is what happens when light goes from less dense to more dense
- d. "not enough information" - We DO have enough information based on the laws of refraction
Verification:
Snell's Law tells us that n₁sin(θ₁) = n₂sin(θ₂), where n is the refractive index (related to density). When n₂ > n₁ (going to a denser medium), sin(θ₂) must be smaller than sin(θ₁), meaning θ₂ < θ₁. A smaller angle means the ray is closer to the normal - it bends toward the normal.
Final Answer: c
Parent Tip: Review the logic above to help your child master the concept of quiz questions with answers on light.
