Answer: e. Christian Dopplerâ
Explanation:
Based on the information given, the scientist of the past that should definitely be included in the exhibit is Christian Dopplera.
He described how the frequency of sound waves and light is being affected by the relative speed of both the source and also the observer. This was referred to as the Doppler effect.
In this scenario, the Doppler effect can be used to show how the universe is expanding. Therefore, the correct option is E.
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
Answer:
<em>50%</em>
Explanation:
Given
Initial power = 200W
Final power = 300W
Increment = 300 - 200 = 100W
percentage increase = increment/initial power * 100
percentage increase = 100/200 * 100%
percentage increase = 0.5 * 100
percentage increase = 50%
<em>Hence the percentage increase in speed is 50%</em>
