# Homework Help: Resonant frequency problem

1. Oct 15, 2016

### Derek1997

1. The problem statement, all variables and given/known data
A 2-year old child has an outer ear length of approximately 1.7 cm (compared to 2.5 cmfor an adult). Find the resonant frequency of the outer ear of the average 2 year old
b.Draw a diagram of the natural harmonic for the child’s ear.
2. Relevant equations
f=v/waveleng
where wavelengt= 4L

3. The attempt at a solution
for a, i used the equation, for baby i got 343/0.068= 5.04KHz am i right?
Also for b, do i need to draw the damped version of the graph? cheers.

2. Oct 15, 2016

### kuruman

You are correct on (a)
For (b) you need to draw the fundamental waveform that you used to answer part (a). I am not sure what you mean by "damped version."

3. Oct 15, 2016

### Derek1997

Hi, so the one on which the graph rises at 5khz and the falls back down. so what i mean is it's moving straightline as it approaches 5khz, it will rise then decrease as we pass the 5. is it right?

4. Oct 15, 2016

### kuruman

5. Oct 15, 2016

### Derek1997

ohhh so you mean the tube one? in which it has a close at one end?

6. Oct 15, 2016

### kuruman

Yes.

7. Oct 16, 2016

### Derek1997

like for you son <3