Question

The air tube pictured below is $2.0$ meters long.
If the speed of sound in the tube is $345m/s$, what is the frequency of the tuning fork producing resonance in the tube if the pictured wave pattern represents the standing wave?

• A. $99Hz$
• B. $173Hz$
• C. $302Hz$
• D. $345Hz$
• E. $690Hz$

Answer 1

Answer: (C)

$302Hz$

Given : $L=2.0$ m $v=345$ m/s

Frequency of turning fork required $\nu =\frac{(2n-1)v}{4L}$ where $n=4$

$\therefore$ $\nu =\frac{(2\times 4-1)\times 345}{4\times 2.0}\approx 302$ $Hz$