Short Answer
Brandon’s sound level is significantly lower than Ahmad’s mower, with Brandon’s sound intensity at 10^-10 watts/m¬¨‚â§ compared to the mower’s 10^-4 watts/m¬¨‚â§. Therefore, Ahmad’s mower is 60 decibels louder than the sound level Brandon can hear, indicating a substantial difference in sound intensity.
Step 1: Understanding Sound Intensity and Decibels
Sound intensity is typically measured in terms of watts per square meter, and the relationship between sound intensity (I) and sound level in decibels (Db) is defined by the formula L = 10 log (I/I0). Here, I0 is the reference sound intensity, which equals 10^-12 watts/m², representing the threshold of hearing for the average human ear. Understanding this foundation is critical for comparing different sound intensities.
Step 2: Measuring Brandon and Ahmad’s Sound Levels
Brandon’s hearing capability is defined at a sound intensity of 10^-10 watts/m¬¨‚â§, while Ahmed’s mower generates a much higher intensity of 10^-4 watts/m¬¨‚â§. To compare these levels accurately, we calculate the ratio of intensities, which shows that Ahmad’s mower is 10^6 (one million times) more intense than the sound Brandon can perceive. This significant difference indicates that the mower operates at a much higher sound intensity level.
Step 3: Calculating the Decibel Difference
Using the logarithmic nature of the decibel scale, we establish that every increase of tenfold in sound intensity results in a 10 decibel increase in loudness. Given that Ahmad’s mower is 10^6 times more intense than Brandon’s sound level, we can apply this relationship:
- The increase in decibels is calculated as follows: 10 log(10^6) = 60 decibels.
- This means Ahmad’s mower is 60 decibels louder than the sound level Brandon can hear.