Physics - Sound Flashcards
What vibrates in a cello?
The strings
What is a place where the air pressure is higher than normal called?
A compression
What is a place where the air pressure is lower than normal called?
A rarefaction
Why did the candle flicker when put next to the loudspeaker?
The vibrations in the air caused by the speaker vibrating caused the candle to flicker [shifting air]
How did the slinky demonstration (pushing it backwards and forwards) show that the compression wave was longitudinal?
The vibration of the coils were the same as the flow of the compressions/energy
Why can you not hear any sounds in space?
Space is a vacuum so there are no air particles for the sound to travel through
In which does sound travel fastest: Solids, Liquids or Gases?
Solids
What is the equation for calculating the speed of sound?
Speed = distance/time
Eg. 165/0.66= 250m/s
What is the equation for the speed of echoes?
Speed = 2x distance/time
Eg. 2 x 230 / 1.36 =338m/s
Name three animals that use echolocation
- Whales
- Bats
- Dolphins
What is frequency?
The frequency of the waves + the pitch
What is amplitude?
The amount of vibrations in a second (measured in Hertz) + the loudness of the sound
What does CRO stand for?
Cathode Ray Oscilloscope
Describe what you can hear for these frequencies.
1-19hz
20hz - 20khz
20-25khz
1-19Hz nothing heard
20Hz - 20KHz getting higher and higher
20-25KHz nothing heard
