esuqugip9498
19.12.2019 •
Physics
The intensity level of a power mower at a distance of 1.0 m is 100 db. you wake up one morning to find that four of your neighbors are mowing their lawn 20 m from your open bedroom window. what is the intensity level in your bedroom? the intensity level of a power mower at a distance of 1.0 m is 100 db. you wake up one morning to find that four of your neighbors are mowing their lawn 20 m from your open bedroom window. what is the intensity level in your bedroom?
a. 50 db
b. 400 db
c. 104 db
d. 80 db
e. 40 db
Solved
Show answers
More tips
- L Leisure and Entertainment Choosing the Right Books to Read: Tips and Recommendations...
- L Leisure and Entertainment What can be considered an antique: defining and valuing old objects...
- B Business and Finance How to Open an Online Store? A Detailed Guide for Beginners...
- C Computers and Internet Log-in: what is it and why do you need it?...
- C Computers and Internet What is the Meaning of lol and How Did it Become Popular?...
- C Computers and Internet Clearing Cache: How to Speed Up Your Browser...
- H Health and Medicine How to Help Men Gain Weight?...
- F Family and Home How to Build a Strong Relationship with Your Child: Tips for Effective Communication...
- L Legal consultation Juvenile Justice: Who Needs It?...
- F Food and Cooking What age is appropriate for giving your child cocoa?...
Answers on questions: Physics
- P Physics An object of mass 0.5 kg is swung in uniform circular motion. the radius is 2 meters, and the force exerted is 4 n. calculate the magnitude of the velocity....
- P Physics What eyeglasses would you prescribe for persons with the following conditions: a near point of 56.6cm? a far point of 56.6cm?...
- P Physics Which has more friction? wax paper, aluminum foil, wood...
- P Physics Acamera flash, which throws a parallel beam of light, has a mirror behind the light bulb. what kind of mirror is it likely to be?...
- P Physics Plants can only cause mechanical weathering. true or false....
- P Physics What describes a sun center solar system...
- P Physics You are heating an iron to iron the shirt you re going to wear to school tomorrow. Which of the following best describes the transformation of energy in this example? Electrical...
- C Chemistry What mass in grams of SO2 is needed to react with 37.50 mol of Oz? 2 SO2 + O2 + 2 H2O → 2 H2SO4 Show your work...
- M Mathematics 3 (7x– 8) how do u do this...
- M Mathematics Bennett spent 4 hours at school today. He attended three 70-minute classes. There is a 5-minute break between classes. Then he ate lunch before going home. How long did Bennett...
Ответ:
β₂ = 74 dB, The answer is D which is the closest
Explanation:
The definition and intensity is the power per unit area
I = P / A
P = I A
The emitted power is constant whereby the energy is distributed over the surface of a sphere
A = 4π R²
We can also write it in two points
P = I₁ A₁ = I₂ A₂
I₁ / I₂ = A₂ / A₁
I₁ / I₂ = 4π R₂² / 4π R₁²
I₁ / I₂ = R₂² / R₁²
The definition of decibels is
β = 10 log (I / I₀)
Let's write this equation for the two given points
m = 1m
β₁ = 10 log (I₁ / I₀)
m = 20m
β₂ = 10 log (I₂ / I₀)
Let's eliminate I₀
β₁ - β₂ = 10 log (I₁ / I₀) - 10 log (I₂ / I₀) = 10 (log (I₁ / I₀) –log (I₂ / I₀))
β₁ - β₂ = 10 log (I₁ / I₂)
β₁ - β₂ = 10 log (R₂² / R₁²)
Let's calculate
100 –β₂ = 10 log (20²/1²)
β₂ = 100 - 10 log 400
β₂ = 100 - 26.0
β₂ = 74 dB
The answer is D which is the closest
Ответ:
2
Explanation:
-1
1 Hz=1 s