Select all that are true about sound waves: Group of answer choices Sound waves cannot travel through a vacuum. Sound waves travel faster through more dense mediums. Sound waves travel faster through the ground than they do the air. Sound waves travel faster through the air than the through the ocean. Sound waves do not have to have a medium to travel. Sound waves travel slower through more dense mediums.
The Correct Answer and Explanation is:
Correct answers:
✅ Sound waves cannot travel through a vacuum.
✅ Sound waves travel faster through the ground than they do the air.
Explanation:
Sound waves are mechanical waves, which means they require a medium — such as a solid, liquid, or gas — in order to travel. This is because sound results from the vibration of particles. In a vacuum, there are no particles to vibrate, so sound cannot propagate in a vacuum. This makes the first statement true.
The speed of sound depends on the type of medium it travels through. It is typically faster in solids, slower in liquids, and slowest in gases. This is primarily due to the differences in particle density and elasticity. In solids like metal or rock, particles are closely packed, allowing vibrations to be transmitted more efficiently from one particle to the next. In contrast, gases have more space between particles, so vibrations take longer to spread. As a result, sound travels faster through the ground (a solid) than through the air (a gas), making the third statement true.
However, it is incorrect to say that sound always travels faster through more dense materials. While density affects sound speed, elasticity plays a more significant role. For example, although water is denser than air, it is also more elastic, which allows sound to travel faster in water than in air. Therefore, sound travels faster through the ocean than through the air, making the fourth statement false.
The idea that sound does not need a medium is false. Sound must have a medium, so any suggestion otherwise is incorrect. Similarly, the claim that sound travels slower through more dense mediums is not always true, so it is also false when stated without context.
Hence, the only correct statements are that sound waves cannot travel through a vacuum and that they travel faster through the ground than through air.
