Question

Part A
During a thunderstorm, lightning can be seen before thunder can be heard. Which statement best describes this phenomenon?
Responses
A Sound is unable to travel through the air.Sound is unable to travel through the air.
B Sound moves much faster than light in the air.Sound moves much faster than light in the air.
C Light moves much slower than sound in the air.Light moves much slower than sound in the air.
D Light moves much faster than sound in the air.Light moves much faster than sound in the air.
Question 2
Part B
If the same sound and light were moving through a different material, what material would allow the sound to move faster than light?
Responses
A Sound always moves faster than light.Sound always moves faster than light.
B A material that is very dense, like a liquid or solidA material that is very dense, like a liquid or solid
C A material that is less dense, like thinner airA material that is less dense, like thinner air
D There is no instance in which sound could travel faster than light.There is no instance in which sound could travel faster than light.

Answer 1

Part A — D. Light moves much faster than sound in the air.
Explanation: Light from lightning reaches your eyes almost instantly (c ≈ 3×10^8 m/s); sound (thunder) travels much slower (~340 m/s in air), so you see lightning before you hear thunder.

Part B — D. There is no instance in which sound could travel faster than light.
Explanation: Even in dense solids or liquids, sound speeds (up to a few km/s) are vastly lower than the speed of light in those media. (Note: specialized lab experiments can slow light dramatically, but under normal conditions taught here, sound never surpasses light.)