Answer:
Option A is correct.
Braylee's music is 3 times louder than Jessica's.
Explanation:
Full Complete Questions
The loudness, L, measured in decibels (Db), of a sound intensity, I, measured in watts per square meter, is defined as
L = 10log (I/I₀), where lo = 10⁻¹² W/m²
and is the least intense sound a human ear can hear.
Jessica is listening to soft music at a sound intensity level of 10⁻⁹ W/m² on her computer while she does her homework.
Braylee is completing her homework while listening to very loud music at a sound intensity level of 10⁻³ W/m² on her headphones. How many times louder is Braylee’s music than Jessica’s?
times louder
3 times louder
30 times louder
90 times louder
Solution
The loudness of a sound intensity is given as
L = 10 log (I/I₀)
For Jessica
I = 10⁻⁹ W/m²
I₀ = 10⁻¹² W/m²
L = 10 log (10⁻⁹/10⁻¹²)
L = 10 log (10³)
L = 10 × 3 = 30 dB
For Braylee
I = 10⁻³ W/m²
I₀ = 10⁻¹² W/m²
L = 10 log (10⁻³/10⁻¹²)
L = 10 log (10⁹)
L = 10 × 9 = 90 dB
How many times louder is Braylee's music than Jessica's?
The factor by which Braylee's music is louder than Jessica's = (90/30) = 3
Braylee's music is 3 times louder than Jessica's.
Hope this Helps!!!