Chapter 10: Sound Flashcards
What is sound?
Sound is a form of energy caused by vibration
What can sound propagate through?
Solid, liquid and gas
Explain the concept of sound propagation.
When something makes a sound, it produces vibration, moving the nearby air molecules that will also vibrate and collide with the air molecules nearby. This vibration is transffered from one molecule to another in form of waves
Put liquid, gas and solid in order of sound transferring speed from rapid to slow
Solid→liquid→gas
What type of surface(s) are good sound reflectors?
Smooth and hard surfaces
What type of surface(s) are good sound absorbers?
Rough and soft surfaces
What does the strength/loudness of sound depends on?
The amplitudes of sound wave
What does the pitch of sound depends on?
Frequency of sound
What is the unit for frequency?
Hertz (Hz)
What is the Doppler effect?
The apperent choice in frequency caused by the relative movement of sound source, relative movement of observer or both
How is an echo produced?
When sound waves are reflected
What is an ultrasound?
A sound higher than 20 000 Hz (which cannot be heard by humans)
Name the sound reflection technology used in shipping industry to detect underwater objects.
Sonar
What is the range of frequency that can be heard by humans?
20-20 000 Hz
Give some devices to overcome human limitations of hearing.
- Hearing aids
- Stethoscope
- Megaphone
