How Does Changing the Medium Affect the Frequencies of Tubes in Sound Physics?

[longestline1]

Homework Statement

A closed tube filled with air is 50cm long.
a. what is the length of an open tube that has the same fundamental frequency? 100cm (34,500cm/s^2 / 2(100cm)
b. what is the frequency? 172.5 (34,500cm/s^2 / 4 (50cm)

I got these two but, need help on this:
c. These two tubes are placed in a gas with a speed of sound grteater than the sound in air. Do the frequencies of their fundamentals remain equal to each other?
d. Do they increase or decrease?

Homework Equations

v/2L (fundamental frequency of the first harmonic, open tube)
v/4L (fundamental frequency of the first harmonic, closed tube)

L = length of tube

The Attempt at a Solution

By CLOSED tube in all these problems - it means closed on ONE SIDE only.

 

[olgranpappy]

Homework Statement

A closed tube filled with air is 50cm long.
a. what is the length of an open tube that has the same fundamental frequency? 100cm (34,500cm/s^2 / 2(100cm)
b. what is the frequency? 172.5 (34,500cm/s^2 / 4 (50cm)

I got these two but, need help on this:
c. These two tubes are placed in a gas with a speed of sound grteater than the sound in air. Do the frequencies of their fundamentals remain equal to each other?
d. Do they increase or decrease?

Homework Equations

v/2L (fundamental frequency of the first harmonic, open tube)
v/4L (fundamental frequency of the first harmonic, closed tube)

L = length of tube

The Attempt at a Solution

By CLOSED tube in all these problems - it means closed on ONE SIDE only.

So, tell us. What is 'v' in the equations you have written?