For a science experiment, you would like to use the Doppler effect to double the perceived frequency of a harmonica, from the 261.7-Hz tone (middle C) that it emits, to 493.9 Hz (B4 note).Calculate the speed the harmonica must have in order for a stationary observer to hear 493.9 Hz.

304.34 m/s

Explanation:

We are given that

Frequency of middle C=f=261.7 Hz

Frequency of B4 emit,f'=493.9 Hz

We have to find the speed of harmonica must have in order for a stationary observer to hear 493.9 Hz.

Speed of sound,v=343 m/s

We know that

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.