A speaker creates uniformly spherical sounds w/ 500 watts of power
a)What is the intensity, I, of the sound at a distance of 20 meters from the speaker? What is the sound intensity level, β, of the sound at a distance of 20 meters from the speaker?
b) What is the intensity, I, of the sound at a distance of 10 meters from the speaker? What is the sound intensity level, β, of the sound at a distance of 10 meters from the speaker?
c) How many deciBels do you increase walking from 20 meters away from the speaker to 10 meters away from the speaker?
c) What power output would the speaker have to put out in order to create 100 dB at a distance 20 meters from the speaker?
Solved
Show answers
More tips
- C Computers and Internet Log-in: what is it and why do you need it?...
- S Style and Beauty Secrets of Tying a Pareo: 5 Ways...
- F Food and Cooking 10 Reasons Why You Should Avoid Giving Re-Gifts: An Informative Guide...
- S Sport How to wrap boxing hand wraps? Everything you need to know!...
- A Animals and plants 5 Tips for Taking Care of Yews to Keep Them Green and Beautiful...
- H Health and Medicine How to Calm Your Nerves? Expert Tips That Actually Work...
- O Other What is a Disk Emulsifier and How Does it Work?...
- S Sport How to Pump Your Chest Muscle? Secrets of Training...
- C Computers and Internet How to Get Rid of 3pic Infector: Everything You Need to Know...
- S Style and Beauty How to Grow Hair Faster: Real Methods and Advice...
Answers on questions: Physics
- P Physics The frequency of a periodic signal is 20 mhz, state it s period?...
- P Physics When changing state, the temperature of a substance remains constant even though energy is supplied. what happens to the energy supplied?...
- P Physics Suppose u(x,t) measures the concentration of a substance in a moving stream (moving with velocity v). suppose the concentration u(x,t) changes both by diffusion and convection;...
- P Physics Suppose you drop a brick from the top of a building that is 250m high. the brick has a mass of 2 kg, and the resistance force fr is given by fr =-40, where u is the velocity...
- P Physics What is the potential energy of a train car that has a mass of 1600 kg sitting 120 meters above the track...
- P Physics A 67 kg man is being pulled away from a burning building as shown in the figure. Calculate the tension T1 on the left side of the rope, in newtons, if the man is in static...
- H History Which term refers to the absence of any government control...
- M Mathematics What is the 3rd term in the sequence and how do you set it up...
- H History Read this list about the characteristics of democracy: recognizing the fundamental worth and dignity of each individual ensuring the equality of all citizens under the...
- M Mathematics Find the value of the radius, x ,to the nearest tenth. a. 3.8 b. 4.2 c. 5.4 d. 3.6 find the value of the diameter, y. a. 10.8 b. 7.2 c. 7.6 d. 8.4...
Ответ:
A) I = 0.09947 W , β = 109 db , B) β = 116 db , β = 116 db , c) Δβ = 7 dB,
D) P = 50.27 W
Explanation:
A) The intensity of a spherical sound wave is
I = P / A
where A is the area of the sphere where the sound is distributed
A = 4π R²
we substitute
I = P / 4πR²
let's calculate
I = 500 / (4π 20²)
I = 0.09947 W
to express this quantity in decibels we use relate
β = 10 log (I / I₀)
The detectivity threshold is I₀ = 1 10⁻¹² W / m²
β = 10 lob (0.09947 / 10⁻¹²)
β = 10 (10.9976)
β = 109 db
B) intensity at r = 10m
I = 500 / (4π 10²)
I = 0.3979 W / m²
β = 10 log (0.3979 / 10⁻¹²)
β = 10 (11.5997)
β = 116 db
C) the change in intensity in decibles is
Δβ = β₁ - β₂
Δβ = 116 - 109
Δβ = 7 dB
D) let's find the intensity for 100 db
I = I₀ 10 (β / 10)
I = 10⁻¹² 10 (100/10)
I = 10⁻² W / m²
Thus
P = I A
P = I 4π R²
P = 10⁻² 4π 20²
P = 50.27 W
Ответ:
C. John Kerry
Explanation: