Physics Questions (1 Viewer)

[GaDaMIt]

I've tried doing these but im lost..

why does sound travel faster in hydrogen than air? just checking about this one.. this is because air is less dense than hydrogen and thus sound travels faster in it right?

why are high frequency sound waves preferred for tasks such as echo location rather than low frequency sound waves?

a baritone and soprano sang into a microphone and the signal produced was fed into a CRO. how would you assign each of these different traces to the correct person?

a consulting sound engineer recommended to the owner of a concert hall that the back wall of the concert hall be curtained with a heavy fabric to eliminate an annoying echo. why might the sound engineer have recommended this approach?

why does sound travel faster in humid air than dry air?

 

[shinji]

q1: yes. sound travels faster in hydrogen than air as there are more particles to interact with the sound waves or something rather like that. i forgot the answer to this.

others im not too sure of. XD

 

[passion89]

A baritone's pitch is very low and soprano pitch is high. When pitch is recorded on a CRO, it can be identified by the frequency of the waves.
If it is a baritone pitch being recorded, the frequency would be low.
If it is a soprano pitch being recorded, the frequency would be much higher.

Remember pitch is related to frequency
volume is related to Amplitude

 

[vizman]

a consulting sound engineer recommended to the owner of a concert hall that the back wall of the concert hall be curtained with a heavy fabric to eliminate an annoying echo. why might the sound engineer have recommended this approach?


multiple echos is known as reverberation. the heavy fabric is an excellent absorber of sound hence, the sound would be dissapated as heat - if it remained say wooden or even concrete the sound would bounce around and reverberate, have a look at the absorption coefficient which gives a perfect absorper a value of 1, heavy fabric would be definately be near this value

 

[Jono_2007]

I've tried doing these but im lost..

why does sound travel faster in hydrogen than air? just checking about this one.. this is because air is less dense than hydrogen and thus sound travels faster in it right?

Incorect. Air is much more dense then hydrogen, So that idea is dead.
The reason is that hydrogen molecules travel faster then air as a mixture, and sound is limited to the velocity of the particles throught which it is traveling.

Jono

 

[vizman]

lol air is like 14 times more dense than hydrogen

 

[airie]

why are high frequency sound waves preferred for tasks such as echo location rather than low frequency sound waves?

I suspect this this because higher frequency waves carry more energy and are less prone to diffraction - a way of losing energy - than low frequency waves, therefore more energy will be reflected back by using high frequency waves.

why does sound travel faster in humid air than dry air?

This is because humid air contains more water vapour, which helps increasing the speed of sound as water molecules have a lighter mass.

 

[Roobs]

High Frequency waves are also preffered for any sort of imaging, ans their smallet wavelength gives better resolution

(i think)

 

[passion89]

why does sound travel faster in humid air than dry air?

The speed of sound in dry air at 0 degrees is around 330m/s or 1200km/h. When there is water vapour in the air, this speed increases because the faster moving molecules bump into each other much more frequently.
In water sound travels about 4 times faster than in air. In a gas, the sound speed depends on the ratio of pressure (tension) to the mass density of the gas.

In other words: Sound travels slower in gas than in water (humidity) because in gas, the molecules are far apart and in water and humid conditions, the molecules are packed much more closely.