Help with daughters homework

[Ali]

I'm sorry to do this, but I'm stumped and I need the help of all of your brains.

My 10 year old daughter has a maths questions that goes like this:

"The sound of an orchestra is about 60 dB. The sound of a helicopter is about twice this. How many dB is the sound of a helicopter?"

She answered "120dB" but I'm not sure that's right because decibels are logarithmic aren't they?

Ahhhhhheadbangheadbang

I'm at a loss of how to explain it even if I am right, so, over to you lot........

 

[Evans Electric]

No idea Ali , I await the answer with interest.

 

[Ali]

Oh good, I'm not the only one lost then.

 

[wooly]

Well if it says "about" twice the volume then there's no specific answer? :coat

 

[Andy™]

I'm sorry to do this, but I'm stumped and I need the help of all of your brains.My 10 year old daughter has a maths questions that goes like this:

"The sound of an orchestra is about 60 dB. The sound of a helicopter is about twice this. How many dB is the sound of a helicopter?"

She answered "120dB" but I'm not sure that's right because decibels are logarithmic aren't they?

Ahhhhhheadbangheadbang

I'm at a loss of how to explain it even if I am right, so, over to you lot........

iirc, each extra 10db is double, so 70db?

not really something i would expect a 10 year old to know, maybe someone older and studying science or something

 

[samson337]

O my word this is for a 10 year old i would say half because you would still here the orchestra in the back ground ,if it were double then you would'nt, Mmm

 

[Ali]

Oh thank goodness I'm not going mad.

It's on a printed worksheet that the school have photocopied from a book and given out as homework. Now I look closer, I can see that she has a tick after her (wrong) answer!

I will bring it to the schools attention tomorrow - can't wait.

 

[sprocketflup]

I'm sorry to do this, but I'm stumped and I need the help of all of your brains.My 10 year old daughter has a maths questions that goes like this:

"The sound of an orchestra is about 60 dB. The sound of a helicopter is about twice this. How many dB is the sound of a helicopter?"

She answered "120dB" but I'm not sure that's right because decibels are logarithmic aren't they?

Ahhhhhheadbangheadbang

I'm at a loss of how to explain it even if I am right, so, over to you lot........

How about 2 orchestras?

 

[steptoe]

shamelessly stolen from here

An increase of the sound level by 3 dB corresponds to a doubling (factor = 2) of sound intensity.An increase of the sound level by 6 dB corresponds to a doubling of the sound pressure.

An increase in the sound level by 10 dB corresponds to the sensation of double the "volume".

HTH

 

[Ali]

Wow, what a great response, thank you all so much.

I will try and get the teacher to understand the problem and not give that homework out again.

I knew I could rely on you guys.

Have a Guinness on me.

 

[kerching]

Teachers eh? what do they know??

'Those that Can do, those that can't TEACH'

Having said that, our youngest is a PE/Games Teacher in the North East and I for one would not like to cross her; always got a hockey stick in her hand. Hope she does not read this.............. :coat

 

[NozSpark]

Wow, what a great response, thank you all so much.I will try and get the teacher to understand the problem and not give that homework out again.

I knew I could rely on you guys.

Have a Guinness on me.

LOL

My daughter had homework printed out from an American site a year or two ago when she was in primary school,,,, loads of American spellings:shakehead

 

[kme]

For added info - a rise in volume of 1dB is approx the minimum difference we can hear - i.e. the difference between 6dB and 6.5dB (or 56dB & 56.5dB) would be indistinguishable

And 10dB increase in sound pressure level is "twice as loud" - as my esteemed colleagues have stated.

 

[steptoe]

no no no KME, as I posted, it gives the sensation of being twice as loud,

I remember a long time ago someone telling me you get to a certain threshold where you cant tell any difference in how loud something is actually getting,

,,,,,,then your ears burst.!

:|

 

[Evans Electric]

LOLMy daughter had homework printed out from an American site a year or two ago when she was in primary school,,,, loads of American spellings:shakehead

Again ,adopting the proverbial accent , not many people know this but when America declared independance , the Founding Fathers sat down and simplified some of the British spelling with the unnesesarry letters such as , colour to color, programme -program etc.

 

[steptoe]

Again ,adopting the proverbial accent , not many people know this but when America declared independance , the Founding Fathers sat down and simplified some of the British spelling with the unnesesarry letters such as , colour to color, programme -program etc.

ok, so made the the letters all the same did they? :slap

and did they have a use for the word programme in those times? :|

 

[Evans Electric]

Ah you missed another two spelling mistakes ( Which tends to happen when I type toooo quickerley)

......when America Dedared independance......

I was of course just testing but not bad for a keyboard with 6 of the letters worn off .

 

[MKS]

I know women can distinguish lower frequencies better than men! Frequencies below sub 20 hz, should be felt rather than heard, hence sub woofer being felt, bag end being one of the view to drop to 8hz!!! Sorry for my completely useless post...