That is actually called the Wave Length.
Answer
given,
Power output of loud train = 100 W
Distance of intensity level from train= 100 m
I₀ = 10⁻¹² W/m²
Intensity of sound = ?
we know,

Intensity level
= 
= 
= 
= 89 dB
Answer:
<em>1.49 x </em>
<em></em>
<em></em>
Explanation:
Kepler's third law states that <em>The square of the orbital period of a planet is directly proportional to the cube of its orbit.</em>
Mathematically, this can be stated as
∝ 
<em>to remove the proportionality sign we introduce a constant</em>
= k
k = 
Where T is the orbital period,
and R is the orbit around the sun.
For mars,
T = 687 days
R = 2.279 x 
for mars, constant k will be
k =
= 3.987 x 
For Earth, orbital period T is 365 days, therefore
= 3.987 x
x 
= 3.34 x 
R =<em> 1.49 x </em>
<em></em>
Answer:
f" = 40779.61 Hz
Explanation:
From the question, we see that the bat is the source of the sound wave and is initially at rest and the object is in motion as the observer, thus;
from the Doppler effect equation, we can calculate the initial observed frequency as:
f' = f(1 - (v_o/v))
We are given;
f = 46.2 kHz = 46200 Hz
v_o = 21.8 m/s
v is speed of sound = 343 m/s
Thus;
f' = 46200(1 - (21/343))
f' = 43371.4285 Hz
In the second stage, we see that the bat is now a stationary observer while the object is now the moving source;
Thus, from doppler effect again but this time with the source going away from the obsever, the new observed frequency is;
f" = f'/(1 + (v_o/v))
f" = 43371.4285/(1 + (21.8/343))
f" = 40779.61 Hz