Page **7** of **21**

### Re: Sounds of Music C

Posted: **November 6th, 2018, 1:30 pm**

by **windu34**

I was wondering, can I use blanks? They are reeds that are not fully shaved so I have to work on them still. They just make it easier than buying normal cane and having to cut it.

I think this is going to be a question best answered by submitting an FAQ to Soinc.org.

Link

### Re: Sounds of Music C

Posted: **November 10th, 2018, 11:11 pm**

by **hippo9**

I know a one octave major scale must be played, but this mean 8 notes (restarting the sequence) or just the regular 7? I ask because the pitch scores would add up to 36 if 8 notes were required, but major scales only have 7 notes.

### Re: Sounds of Music C

Posted: **November 11th, 2018, 6:15 am**

by **mjcox2000**

I know a one octave major scale must be played, but this mean 8 notes (restarting the sequence) or just the regular 7? I ask because the pitch scores would add up to 36 if 8 notes were required, but major scales only have 7 notes.

A major scale consists of 8 notes, not 7 — it contains the tonic in two different octaves.

### Re: Sounds of Music C

Posted: **November 11th, 2018, 7:23 am**

by **hippo9**

I know a one octave major scale must be played, but this mean 8 notes (restarting the sequence) or just the regular 7? I ask because the pitch scores would add up to 36 if 8 notes were required, but major scales only have 7 notes.

A major scale consists of 8 notes, not 7 — it contains the tonic in two different octaves.

Ok thanks! I was just making sure because the scales only have 7 distinct notes.

### Re: Sounds of Music C

Posted: **November 13th, 2018, 7:16 pm**

by **SciolyHarsh**

Haven't been able to find out how to reach the correct answer for this question. So, the first question is:

At a party, there is a louder stereo blaring some dank music. I'm a party animal so I'm standing 1 meter away from the stereo and I perceive a sound intensity of 10^-1

, what is the approximate decibel level that I perceive to the nearest tenth?

So I got 110 dB for this, from doing I(dB)=10log(I/I*). I'm not able to get a correct answer for part 2, which is:

You are more far away, 20 meters, because you are a normal person, what is the sound intensity you perceive and the approximate decibel level?

My answer for the sound intensity is 1/4000

and 83.979 dB for the decibel level. The answer key says it's 0.00025 dB and 10^-3

.

How would you get the correct answers for part 2?

### Re: Sounds of Music C

Posted: **November 13th, 2018, 7:20 pm**

by **UTF-8 U+6211 U+662F**

Haven't been able to find out how to reach the correct answer for this question. So, the first question is:

At a party, there is a louder stereo blaring some dank music. I'm a party animal so I'm standing 1 meter away from the stereo and I perceive a sound intensity of 10^-1

, what is the approximate decibel level that I perceive to the nearest tenth?

So I got 110 dB for this, from doing I(dB)=10log(I/I*). I'm not able to get a correct answer for part 2, which is:

You are more far away, 20 meters, because you are a normal person, what is the sound intensity you perceive and the approximate decibel level?

My answer for the sound intensity is 1/4000

and 83.979 dB for the decibel level. The answer key says it's 0.00025 dB and 10^-3

.

How would you get the correct answers for part 2?

You are correct. Ignore the answer key.

### Re: Sounds of Music C

Posted: **November 13th, 2018, 7:58 pm**

by **SciolyHarsh**

Haven't been able to find out how to reach the correct answer for this question. So, the first question is:

At a party, there is a louder stereo blaring some dank music. I'm a party animal so I'm standing 1 meter away from the stereo and I perceive a sound intensity of 10^-1

, what is the approximate decibel level that I perceive to the nearest tenth?

So I got 110 dB for this, from doing I(dB)=10log(I/I*). I'm not able to get a correct answer for part 2, which is:

You are more far away, 20 meters, because you are a normal person, what is the sound intensity you perceive and the approximate decibel level?

My answer for the sound intensity is 1/4000

and 83.979 dB for the decibel level. The answer key says it's 0.00025 dB and 10^-3

.

How would you get the correct answers for part 2?

You are correct. Ignore the answer key.

Thank you! I spent so much time stressing over a wrong key!

### Re: Sounds of Music C

Posted: **November 15th, 2018, 6:40 pm**

by **SciolyHarsh**

One more question!

This one also has two parts.

A nylon string on a violin has a density of 1200 kg/m^3 with a diameter of 4x10^-3 meters. The string is held with a tension of 220 N and the frequency of the first harmonic of the G string is 196 Hz. What is the length of the string?

So I solved this and got 0.308 m, which is correct, but I don't know how to solve the next part.

If we wanted to play one octave up on the open string from the fundamental G in question 12, how much do we need to increase the tension?

### Re: Sounds of Music C

Posted: **November 16th, 2018, 4:35 am**

by **TheSquaad**

One more question!

This one also has two parts.

A nylon string on a violin has a density of 1200 kg/m^3 with a diameter of 4x10^-3 meters. The string is held with a tension of 220 N and the frequency of the first harmonic of the G string is 196 Hz. What is the length of the string?

So I solved this and got 0.308 m, which is correct, but I don't know how to solve the next part.

If we wanted to play one octave up on the open string from the fundamental G in question 12, how much do we need to increase the tension?

You double the frequency to go up an octave. Because tension is square routed, it needs to multiply by a factor of 4 to increase frequency by a factor of 2

### Re: Sounds of Music C

Posted: **November 25th, 2018, 1:43 pm**

by **CaTaStRoPhY**

The rule manual mentions "Basic terminology regarding sound, sound production, and related science terms". What does this mean, specifically? Anyone have resources for this section?