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

Answer:

1.4 Hz

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

$f_{obs}= f_{obs}\left ( \frac{V+ v}{V - v} \right )$

$f_{obs}= (269)\left ( \frac{343 + 0.9}{343 - 0.9} \right )$

$f_{obs} = 270.4$

Beat frequency is given as

Δf = $f_{obs} - [tex]f_{actual}$

Δf = 270.4 - 269

Δf = 1.4 Hz