Amplitude and intensity of rock concert

In summary, the engineer turns up the amplifiers by 87.0% at a rock concert, resulting in a 3.4225 times increase in intensity. However, to find the percentage increase in intensity, the formula (I1-I2)/I1 should be used instead of (A2/A1)^2. This results in a 242% increase in intensity.
  • #1
L1988
11
0

Homework Statement



At a rock concert, the engineer decides that the music isn't loud enough. He turns up the amplifiers so that the amplitude of the sound, where you're sitting, increases by 87.0%. By what percentage does the intensity increase? Do not enter unit.

Homework Equations




I used the fact that intensity is proportional to amplitude squared.

(A2/A1)^2 = I2/I1


The Attempt at a Solution



85% increase in A, so:

(1.85)^2=I2/I1

3.4225=I2/I1

I2=3.4225I1

3.4225x100= 342%

342%-100% = 242%

Answer=242 <-- which is incorrect.

where did I make my mistake?
 
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  • #2
Hey there,

For a start is it 87% or 85%?

L1988 said:
..increases by 87.0%
L1988 said:
..85% increase in A, so:
 
Last edited:
  • #3
the problem is that you didn't compute the percent by using a percent difference. All of your work is right but you need to use (I1-I2)/I1 = percent difference, use this instead of a straight fraction like you calculated. if you use this equation you will get the desired answer.
 

1. What is the difference between amplitude and intensity in the context of a rock concert?

Amplitude refers to the maximum displacement of particles in a sound wave, while intensity refers to the amount of energy carried by the sound wave. In a rock concert, amplitude would refer to the height of the sound waves produced by the speakers, while intensity would refer to the overall loudness of the music.

2. How do amplitude and intensity affect the overall experience of a rock concert?

Amplitude and intensity play a crucial role in creating the atmosphere and energy of a rock concert. The higher the amplitude, the more powerful and immersive the music will feel. Similarly, a higher intensity will result in a louder and more energetic concert experience.

3. Can the amplitude and intensity of a rock concert be harmful to human hearing?

Yes, high levels of amplitude and intensity can be damaging to human hearing, especially when exposed to them for extended periods. It is important to wear ear protection at concerts to prevent hearing loss.

4. How do sound engineers control the amplitude and intensity of a rock concert?

Sound engineers use a variety of tools and techniques to control the amplitude and intensity of a rock concert. This includes adjusting the levels on the soundboard, using speakers with different wattage, and strategically placing speakers around the venue to achieve the desired sound.

5. Is there a standard or recommended amplitude and intensity for rock concerts?

There is no standard or recommended amplitude and intensity for rock concerts as it largely depends on the preferences of the performers and the type of music being played. However, most venues and sound engineers follow safety regulations and guidelines to ensure the sound levels do not exceed harmful levels for the audience.

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