Question

A student holds a tuning fork oscillating at 269 Hz. He walks toward a wall at a constant speed of 0.9 m/s. What beat frequency does he observe between the tuning fork and

Answer 1

1.4 Hz

Step-by-step explanation:

`f_(actual)` = actual frequency emitted from the tuning fork = 269 Hz

`f_(obs)` = frequency observed

Δf = beat frequency

v = speed of walk = 0.9 m/s

V = speed of sound = 343 m/s

Observed frequency is given as

`f_(obs)= f_(obs)\left ( (V+ v)/(V - v) \right )`

`f_(obs)= (269)\left ( (343 + 0.9)/(343 - 0.9) \right )`

`f_(obs) = 270.4`

Beat frequency is given as

Δf =
`f_(obs) - [tex]f_(actual)`

Δf = 270.4 - 269

Δf = 1.4 Hz