| A | B |
|---|
| wave | disturbance that transfers energy from one location to another |
| energy | Waves transport ____ but not matter. |
| matter | Waves transport energy but not ____. |
| mechanical | ____ waves need a medium. |
| medium | Mechanical waves need a ____. |
| solid | The ground is an example of a ____ medium. |
| liquid | Water is an example of a ____ medium. |
| air | Mediums can be solid, liquid or ___. |
| transverse | A ____ wave is a wave in which particles move up and down or side-to-side at right angles (perpendicular) to the direction the wave travels. |
| perpendicular | right angles |
| up and down | A transverse wave is a wave in which particles move ____ or side-to-side at right angles to the direction the wave travels. |
| side-to-side | A transverse wave is a wave in which particles move up and down or ____ at right angles to the direction the wave travels. |
| direction | A transverse wave is a wave in which particles move up and down or side-to-side at right angles to the ____ the wave travels. |
| longitudinal | A ____ wave is a wave in which particles move back and forth in the same direction (parallel) as the wave travels. |
| back and forth | A longitudinal wave is a wave in which particles move ___ in the same direction as the wave travels. |
| parallel | same direction |
| same | A longitudinal wave is a wave in which particles move back and forth in the ____ direction as the wave travels. |
| sound waves | ____ that travel through air are longitudinal. |
| wavelength | distance between a point on one wave and the same point on the next wave (can be crest to crest, trough to trough, etc.) |
| crest to crest | A wavelength can be ____ or trough to trough. |
| trough to trough | A wavelength can be crest to crest or ____. |
| frequency | number of waves that pass a point in one second |
| one second | Frequency is the number of waves that pass a point in ____. |
| pass a point | Frequency is the number of waves that ____ in one second. |
| hertz | unit of measurement for wave frequencies |
| Hz | abbreviation for Hertz |
| amplitude | distance from the rest position to the crest or trough of a wave |
| rest position | Amplitude is the distance from the ____ to the crest or trough of a wave. |
| amount of energy | Amplitude is related to the ____ carried by the wave. |
| higher | The ___ the energy, the greater the amplitude. |
| greater | The higher the energy, the ___ the amplitude. |
| lower | The ____ the energy, the lower the amplitude. |
| sound | ____ waves are created when objects vibrate. |
| vibrate | Sound waves are created when objects ____. |
| compression | area of a sound wave where air particles are close together |
| close | Compression is an area of a sound wave where air particles are ____ together. |
| forward motion | Compression is caused by ____ of air particles. |
| air particles | Compression is caused by forward motion of ____. |
| high | Compression is an area of ___ air pressure. |
| rarefaction | area of a sound wave where air particles are spread out |
| spread out | Rarefaction is an area of a sound wave where air particles are ____. |
| low | Rarefaction is an area of ____ air pressure. |
| pitch | related to the frequency of a sound wave |
| high frequency | High-pitched sounds have a ____. |
| low frequency | Low-pitched sounds have a ____. |
| animals | Different ___ can hear different pitches. |
| different | Different animals can hear ____ pitches. |
| elephants | ____ can hear lower pitches. |
| porpoises | ____ can hear higher pitches. |
| intensity | related to the amplitude of a sound wave |
| higher intensity | = higher amplitude |
| lower intensity | = lower amplitude |
| loud or soft | Intensity relates to how ____ a sound is. |
| decibels | Intensity is measured in units called decibels. |
| dB | abbreviation for decibels |
| liquids and solids | Sound waves travel faster through most ____ than air. |
| faster | Sound waves travel ___ through most liquids and solids than air. |
| Doppler effect | the apparent change in frequency of a wave due to the motion of the source |
| source | When the ____ of the sound moves toward you, the sound waves also move toward you. |
| toward | When the source of the sound moves ____ you, the sound waves also move ____ you. |
| shorter | When the wavelengths are ____, the frequency is higher. |
| higher | When the frequency is ____. the pitch seems _____. |
| away | When the source of the sound moves ____ from you, the souce is moving in the opposite direction from the sound waves that reach you. |
| opposite | When the source of the sounds moves away from you, the source is moving in the ____ direction from the sound waves that reach you. |
| longer | When the wavelengths are ____, the frequency is lower. |
| lower | When the frequency is ____, the pitch seems ____. |
| ahead | The pitch of a siren seems higher ___ of the car as it approaches you. |
| behind | The pitch of a siren seems lower ____ the car after it passes you. |
| approaches | The pitch of a siren seems higher ahead of the car as it ____ you. |
| passes | The pitch of a siren seems lower behind the car after it ____ you. |
| motion | The pitch of a siren appears to change because its source (a car) is in ____. |
