Sounds of Music C

[Giantpants]

1. An airplane is flying at a height of 11,000 m. Given that the temperature outside the airplane is -56.5ºC, what is the speed of sound outside the airplane?
2. Given the frequency of A3 is 250 Hz, what is the frequency of C4?

1. 297 m/s
2. 297 Hz again? Lol

[linzhiyan]

1. An airplane is flying at a height of 11,000 m. Given that the temperature outside the airplane is -56.5ºC, what is the speed of sound outside the airplane?
2. Given the frequency of A3 is 250 Hz, what is the frequency of C4?

1. 297 m/s
2. 297 Hz again? Lol

I agree with 2, but I got 295 m/s for 1... (You may want to check my work because uhh... yeah lol)

[will0416]

Depends on your formula. I got 297 m/s using the simplified 331+0.6(temp) formula and I got 295 m/s using the more exact formula that includes the square root (c = 331.3 × √ (1 + (ϑ / 273.15)))

[Giantpants]

I used the simplified formula, but it’s good to know about the other too!

Anyway, what is the speed of sound in a material with a bulk modulus of elasticity of 9.4 E8 N/m^2, and a density of 270 kg/m^3?

EDITS: Just realized it said M/m^2 for like two months. Oops. Anyway rip this question marathon sorry D:

[bernard]

I used the simplified formula, but it’s good to know about the other too!

Anyway, what is the speed of sound in a material with a bulk modulus of elasticity of 9.4 E8 N/m^2, and a density of 270 kg/m^3?

EDITS: Just realized it said M/m^2 for like two months. Oops. Anyway rip this question marathon sorry D:

Click to Show Answer

The speed of sound is  where  is the bulk modulus of elasticity and  is the density. This calculates to c = 1.9 km/s.

[Giantpants]

I used the simplified formula, but it’s good to know about the other too!

Anyway, what is the speed of sound in a material with a bulk modulus of elasticity of 9.4 E8 N/m^2, and a density of 270 kg/m^3?

EDITS: Just realized it said M/m^2 for like two months. Oops. Anyway rip this question marathon sorry D:

Click to Show Answer

The speed of sound is  where  is the bulk modulus of elasticity and  is the density. This calculates to c = 1.9 km/s.

Yep, looks good! Your turn I guess? Lol or whoever else wants to go can.

[smayya337]

I'll write a quick one:

I'm walking into school one morning at 1.5 m/s when my friend Spencer, standing on the other side of the auditorium lobby, decides it would be a good idea to take off Naruto running at 2.5 m/s in my direction while screaming an equally-tempered E5. Just another morning at TJ.

Note: Assume c = 343 m/s.

a. What frequency do I hear his shrieking as?
b. What pitch is this?
c. Is it sharp or flat?
d. How many (to the nearest 0.1) cents sharp or flat is this?

Bonus: What two instruments does Spencer play?

[Nydauron]

I'll write a quick one:

I'm walking into school one morning at 1.5 m/s when my friend Spencer, standing on the other side of the auditorium lobby, decides it would be a good idea to take off Naruto running at 2.5 m/s in my direction while screaming an equally-tempered E5. Just another morning at TJ.

Note: Assume c = 343 m/s.

a. What frequency do I hear his shrieking as?
b. What pitch is this?
c. Is it sharp or flat?
d. How many (to the nearest 0.1) cents sharp or flat is this?

Bonus: What two instruments does Spencer play?

Click to Show Answer

a. Doppler effect for APPROACHING objects: 
    An equal-tempered E5 is 659.3 Hz.
    Plug and chug:
    
    
b. This is still an E5
c.  It is sharp
d. Cents equation: 
    Plug and chug:
    
    

As for the bonus ...I would guess either the piccolo trumpet or piccolo, and I'd probably throw in the recorder as well lol

[smayya337]

I'll write a quick one:

I'm walking into school one morning at 1.5 m/s when my friend Spencer, standing on the other side of the auditorium lobby, decides it would be a good idea to take off Naruto running at 2.5 m/s in my direction while screaming an equally-tempered E5. Just another morning at TJ.

Note: Assume c = 343 m/s.

a. What frequency do I hear his shrieking as?
b. What pitch is this?
c. Is it sharp or flat?
d. How many (to the nearest 0.1) cents sharp or flat is this?

Bonus: What two instruments does Spencer play?

Click to Show Answer

a. Doppler effect for APPROACHING objects: 
    An equal-tempered E5 is 659.3 Hz.
    Plug and chug:
    
    
b. This is still an E5
c.  It is sharp
d. Cents equation: 
    Plug and chug:
    
    

As for the bonus ...I would guess either the piccolo trumpet or piccolo, and I'd probably throw in the recorder as well lol

Sorry for not responding sooner! Yeah, that looks about right for a through d. For the bonus, Spencer is actually a pretty good trumpet player and arguably an even better pianist. He also sings (and probably plays the recorder too, it wouldn't surprise me). Your turn!

[Nydauron]

I am about to play the Bach Preludio in E Major in my lesson. I couldn't play by memory, so here is the sheet music on IMSLP. However, I forgot to tune. (I also didn't warm up silly me!) I start to play the beginning, and my teacher covered her ears to prevent them from bleeding out due to the horrible intonation. "STOP!! Did you even tune your strings?!" she repulsed, "Your E string is a quarter of a semitone flat!!!" (She has perfect pitch down to the cent )

a) How many cents was I off by?
b) Given that I started on the E string and that my left pinkie was in the correct place, what note did I play and at what frequency was it? (Big hint: the music is a good starting point!) (EVEN BIGGER HINT: my finger was placed on the string halfway between the nut and the bridge)
c) What is the interval of the first two notes of Bach's Preludio called?
Violinist only question (for ez brownie pts!): What's your fingering for the first line? No wrong answer here. or is there...