Answer:
Explanation:
In the decibel scale , intensity of sound changes logarithmically as follows
Value in decibel scale , the value of I₀ = 10⁻¹² W /m².
Putting the values
W/m²
Similarly for 54 dB sound intensity can be given as follows
I = 10⁻¹² x 
W / m²
For intensity of sound the relation is as follows
I = 2π²υ²A²ρc where υ is frequency , A is amplitude , ρ is density of air and c is velocity of sound .
Putting the given values for 71 dB
= 2π² x 504²xA²x 1.21 x 346
A² = 60.03 x 10⁻¹⁶
A = 7.74 x 10⁻⁸ m
For 54 dB sound
= 2π² x 504²xA²x 1.21 x 346
A² = 1.1978 x 10⁻¹⁶
A = 1.1 x 10⁻⁸ m
The Kinetic<span> Molecular </span>Theory<span> explains the forces between </span>molecules<span> and the energy that </span>they<span> possess.
</span>
Answer:
915 Hz
Explanation:
The observed frequency from a sound source is given as
f₀ = f [(v + v₀)/(v+vₛ)]
where
f₀ = observed frequency of the sound by the observer = ?
f = actual frequency of the sound wave = 983 Hz
v = actual velocity of the sound waves = 343 m/s
vₛ = velocity of the source of the sound waves = 55.9 m/s
v₀ = velocity of the observer = 28.4 m/s
f₀ = 983 [(343+28.4)/(343+55.9)]
f₀ = 915.2 Hz = 915 Hz
♥ C) 94%
♥ If the work put into a lever is 930 joules and the work accomplished is 870 joules, the efficiency of the lever is 94%.
♥ <span>870/930=93.5
</span>♥ And rounded you get 94.
