Sound and medium

[chiddler]

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will try asking somebody first. if unsuccessful will reask questions in a less intimidating manner. <3

 

[silverice]

will try asking somebody first. if unsuccessful will reask questions in a less intimidating manner. <3

Maybe you should ask anyways, so that we can learn as well?😀

 

[MedPR]

Maybe you should ask anyways, so that we can learn as well?😀

chiddler is trying to get a leg up on us by not sharing hard questions 🙂

 

[chiddler]

lol. was a behemoth of a post. Still have not asked so answers are appreciated:


Formula given is the following:

velocity of sound in a medium, v = sqrt(gamma P/?)
gamma = Cp/Cv. Cp = molar heat capacity at constant pressure. Cv = at constant volume. However, the book gives a nice simple monoatomic gamma = 1.67, diatomic = 1.40, triatomic = 1.33.
P = pressure
? = density

and a "general relationship"
v a sqrt(restoring force, or molecular KE / molecular weight)

Questions.
1. I remember not understanding gamma and Cp Cv from physics class too lol. Should I understand this variable for mcat? If so, would like an explanation of what Cp and Cv are, please.

2. If change gas from H2 to O2, does speed of sound increase? The formula suggests both increase because more pressure with a heavier gas (because more momentum of heavier gas molecules, right?) but also decrease because more density of air.

The general relationship and the book say it will decrease. What happens and why?

Thank yous.

ninja 3: If have two gases at same temperature and pressure, but different molecular weights, is their kinetic energy the same?

 

[MedPR]

lol. was a behemoth of a post. Still have not asked so answers are appreciated:


Formula given is the following:

velocity of sound in a medium, v = sqrt(gamma P/?)
gamma = Cp/Cv. Cp = molar heat capacity at constant pressure. Cv = at constant volume. However, the book gives a nice simple monoatomic gamma = 1.67, diatomic = 1.40, triatomic = 1.33.
P = pressure
? = density

and a "general relationship"
v a sqrt(restoring force, or molecular KE / molecular weight)

Questions.
1. I remember not understanding gamma and Cp Cv from physics class too lol. Should I understand this variable for mcat? If so, would like an explanation of what Cp and Cv are, please.

2. If change gas from H2 to O2, does speed of sound increase? The formula suggests both increase because more pressure with a heavier gas (because more momentum of heavier gas molecules, right?) but also decrease because more density of air.

The general relationship and the book say it will decrease. What happens and why?

Thank yous.

ninja 3: If have two gases at same temperature and pressure, but different molecular weights, is their kinetic energy the same?

Oh, I saw this earlier and ignored it because I have no idea.

As to your last question. if KE = 1/2mv^2, I'd imagine two gases with different molecular weights at the same temperature would have different KE.