Week 4 Sound Waves A. TRUE or FALSE: Identify the following statements as being either true (T) or false (F). __________1. Sound waves are longitudinal waves. __________2. As the teacher talks, students hear the voice because particles of air move from the mouth of the teacher to the ear of the student. __________3. Sound waves are mechanical waves. __________4. All sound waves are produced by a vibrating object. __________5. A sound wave does not consist of crests and troughs.
The Correct Answer and Explanation is:
Here are the correct answers to the Week 4 Sound Waves True or False section:
1. Sound waves are longitudinal waves. — True
2. As the teacher talks, students hear the voice because particles of air move from the mouth of the teacher to the ear of the student. — False
3. Sound waves are mechanical waves. — True
4. All sound waves are produced by a vibrating object. — True
5. A sound wave does not consist of crests and troughs. — True
Explanation
Sound waves are a type of wave that travel through a medium such as air, water, or solids. They are classified as longitudinal waves, which means that the particles of the medium vibrate parallel to the direction in which the wave travels. This is different from transverse waves, like light waves, where particles move perpendicular to the direction of wave propagation. So, statement 1 is true.
In statement 2, it suggests that air particles move from the teacher’s mouth directly to the student’s ear. This is false because particles in a sound wave do not travel across space with the wave. Instead, each particle vibrates back and forth in place, passing on the energy to neighboring particles. It is the energy that moves, not the particles themselves.
Statement 3 is true because sound waves are mechanical waves, meaning they require a medium to travel. They cannot propagate through a vacuum because there are no particles to transfer the energy.
Statement 4 is also true. All sound waves are generated by vibrating objects. For example, vocal cords vibrate to create speech, and a guitar string vibrates to produce sound.
Statement 5 is true. Unlike transverse waves, which feature crests and troughs, sound waves consist of compressions and rarefactions. Compressions are regions where particles are close together, while rarefactions are regions where particles are spread apart.
Understanding these properties helps in recognizing how sound behaves and how it differs from other wave types in physics.
