Question

practice it!
a scientist decided to test how light waves and sound waves would be affected by different materials.
for one part of the experiment, the material seen in the picture was used. the light waves and sound waves were sent through the air before entering this material.
select the statement(s) that accurately describe results that you would expect the scientist to get in this experiment using the material shown.
light waves would slow down in the material while sound waves would speed up in the material.
light waves and sound waves would travel at the same speed through the material.
light waves and sound waves would travel at different speeds through the material.
light waves would speed up in the material while sound waves would slow down in the material.
light waves and sounds waves would both change their speeds when changing mediums.

Explanation:

• Light waves slow down when moving from air (less - dense medium) to a denser medium (like the material in the experiment). Sound waves, on the other hand, generally speed up when moving from a less - dense medium (air) to a denser medium (many solids or liquids). So, their speeds change in opposite ways when changing mediums, meaning they travel at different speeds through the material. Also, both light and sound waves change their speeds when changing mediums.
• Light and sound have different natures (electromagnetic vs. mechanical pressure waves). Light has a very high speed in vacuum (\(c = 3\times10^{8}\ m/s\)) and its speed is reduced in denser media. Sound speed in air is about \(v_{air}\approx343\ m/s\) and is higher in many solids (\(v_{solid}>v_{air}\)).

Answer:

• A. Light waves would slow down in the material while sound waves would speed up in the material.
• C. Light waves and sound waves would travel at different speeds through the material.
• E. Light waves and sounds waves would both change their speeds when changing mediums.