Waves, Sound & Light Flashcards
1
Q
Frequency
- symbol
- units
- meaning
A
- f
- hertz (Hz)
- the number of waves that pass a point in one second.
2
Q
Wavelength
- symbol
- units
- meaning
A
- upside down Y
- metres (m)
- the distance from one Crest (or trogh) to the next
3
Q
Wave speed
- symbol
- units
- meaning
A
- V
- m/s or ms`1
- the distance travelled by a wave per second.
4
Q
Amplitude
- symbol
- units
- meaning
A
- A
- metres (m)
- height of a aave from the middle to the top.
5
Q
What frequency of sound can humans hear?
A
Humans can hear between 20Hz and 20000Hz.
6
Q
What is sound above 20000Hz called?
A
Ultrasound
7
Q
What is the danger level for sound (humans)
A
80dB
8
Q
What should be worn to protect ears from high sound levels?
A
Ear protectors
9
Q
What is sound level measured in?
A
dB
Decibels
10
Q
What is the accepted value for the speed of sound in air?
A
340m/s
11
Q
What is the speed of light in air?
A
3.0 × 10^8 m/s
300 million metres per second
12
Q
What value is the threshold of hearing?
A
0dB
