Question

if 20 beats are produced within one second, which of the following frequencies could possibly be held by two sound waves traveling through a medium along a common path at the same time?
a) 22 hz and 42 hz
b) 38 hz and 63 hz
c) 47 hz and 55 hz
d) 18 hz and 26 hz

Explanation:

Step1: Recall beat frequency rule

Beat frequency $f_{beat} = |f_1 - f_2|$, where $f_{beat}=20$ Hz.

Step2: Calculate difference for Option A

$|42 - 22| = 20$ Hz

Step3: Calculate difference for Option B

$|63 - 38| = 25$ Hz

Step4: Calculate difference for Option C

$|55 - 47| = 8$ Hz

Step5: Calculate difference for Option D

$|26 - 18| = 8$ Hz

Answer:

A) 22 Hz and 42 Hz