Samuel Bexelius 8c Flashcards
(43 cards)
What is a longitudinal wave?
A type of wave in which the particles of the medium move parallel to the direction of the wave’s motion.
An example is sound waves in air.
What is a transverse wave?
A type of wave in which the particles of the medium move perpendicular to the direction of the wave’s motion.
An example is light waves.
How is sound generated?
Sound is created when something vibrates.
For example, when a guitar string is plucked.
How does sound travel?
Sound travels through vibrations of air particles that bump into each other and carry sound waves.
This occurs when an object vibrates.
What does sound need for transmission?
A medium such as air, water, or solid materials.
Unlike light, sound cannot travel through space.
What is the human audible frequency range?
About 20 Hz to 20,000 Hz.
Sounds outside this range are not audible to humans.
What is infrasound?
Sound waves with frequencies lower than 20 Hz.
It can be used in earthquake detection.
What is ultrasound?
Sound waves with frequencies higher than 20,000 Hz.
It’s used in medical imaging, like pregnancy scans.
How do elephants use infrasound?
They communicate over long distances using infrasound.
How do bats and dolphins use ultrasound?
They use it for echolocation to find prey and navigate.
What is one medical application of ultrasound?
Used to view inside the body, like during pregnancy scans.
What is noise?
An unwanted sound that can be annoying or harmful.
It can cause stress, sleep problems, and hearing damage.
How is sound loudness measured?
In decibels (dB) using a sound level meter.
What decibel level can cause hearing loss?
Over 85 dB.
What is noise reduction?
The process of reducing unwanted sound.
Name three sources of noise pollution.
- Traffic
- Construction sites
- Loud music
How can noise be reduced in homes?
- Use carpets
- Use curtains
- Install double-glazed windows
What is the importance of hearing protection?
To prevent hearing loss from loud sounds.
What are disturbing sounds?
Noises that cause discomfort, like loud traffic or a crying baby.
How can disturbing sounds affect people?
They can cause stress, irritability, and affect concentration.
What is the Doppler effect?
It occurs when a sound source moves towards or away from you, altering the pitch of the sound.
How does sound reflect off hard surfaces?
It bounces back as an echo.
How does sonar work?
It sends out sound waves and measures the time it takes for them to bounce back.
What do microphones do?
They convert sound into electrical signals.
