Characteristics ofWaves
True or False
Determine if the following statements are true or false.
_____ 1. A mechanical wave starts with a disturbance in matter.
_____ 2. Particles of matter actually travel along with a mechanical wave.
_____ 3. Transverse waves travel only through solid matter.
_____ 4. Earthquakes cause longitudinal waves.
_____ 5. In a surface wave, particles of the medium move only up and down.
_____ 6. Ocean waves crash on shore when the bottoms of the waves slow down due to friction.
_____ 7. All waves transfer energy from one place to another.
_____ 8. All mechanical waves are either transverse or longitudinal waves.
_____ 9. Some waves do not require a medium.
_____ 10. A source of energy is needed to start a mechanical wave.
Critical Reading
Read this passage from the text and answer the questions that follow.
MechanicalWaves
A mechanical wave is a disturbance in matter that transfers energy from place to place. A mechanical wave startswhen matter is disturbed. Consider what happens when a drop of water falls into a pond. This disturbs the water inthe pond. Then the disturbance travels outward from the drop in all directions. This is the wave. A source of energyis needed to start a mechanical wave. In this case, the energy comes from the falling drop of water.
The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media).The medium in the example just described is a liquid—the water in the pond. But the medium of a mechanical wavecan be any state of matter, including a solid or a gas. It’s important to note that particles of matter in the mediumdon’t actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or moveback-and-forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate,they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next tothem, and so on.
Questions
1. Define mechanical wave.
2. How does a mechanical wave begin?
3. What is the medium of a mechanical wave?
4. Describe how particles of the medium move when a mechanical wave passes through them.
Multiple Choice
Circle the letter of the correct choice.
1. Types of mechanical waves include
a. longitudinal waves.
b. transverse waves.
c. surface waves.
d. all of the above
2. The medium of a mechanical wave can be a
a. gas.
b. solid.
c. liquid.
d. any of the above
3. The crests of a transverse wave are like the
a. crests of a primary wave.
b. troughs of a longitudinal wave.
c. rarefactions of a secondary wave.
d. compressions of a longitudinal wave.
4. Examples of mechanical waves include all of the following except
a. ocean waves.
b. sound waves.
c. waves in a rope.
d. electromagnetic waves.
5. Waves that an earthquake sends through rocks underground include
a. tsunami waves.
b. transverse waves.
c. longitudinal waves.
d. two of the above
6. Which of the following statements about ocean waves is true?
a. They travel on the surface of the water.
b. They travel deep underwater.
c. They are secondary waves.
d. They are primary waves.
7. You generate a longitudinal wave when you
a. shake a spring up and down.
b. shake a rope up and down.
c. push and pull a spring.
d. two of the above
Matching
Match each definition with the correct term.
Definitions
_____ 1. disturbance in matter that transfers energy from place to place
_____ 2. part of a longitudinal wave where particles of the medium are spread farthest apart
_____ 3. wave in which particles of the medium vibrate at right angles to the direction that the wave travels
_____ 4. combined transverse and longitudinal wave
_____ 5. part of a transverse wave where particles of the medium are lowest
_____ 6. wave in which particles of the medium vibrate in the same direction that the wave travels
_____ 7. matter through which a mechanical wave travels
Terms
a. longitudinal wave
b. trough
c. mechanical wave
d. medium
e. surface wave
f. rarefaction
g. transverse wave
Fill in the Blank
Fill in the blank with the appropriate term.
1. A wave in a rope is an example of a(n) ______wave.
2. The highest parts of a transverse wave are called ______.
3. A(n) ______wave is a transverse wave that occurs with earthquakes.
4. The parts of a longitudinal wave where particles of the medium are closest together are called ______.
5. A(n) ______wave is a longitudinal wave that occurs with earthquakes.
6. Ocean waves are ______waves.
7. In a(n) ______wave, particles of the medium move in a circular motion.