Final answer:
The sound level for a noise with an intensity of 9.9 x 10^-12 watts/m² is approximately 10 dB, using the reference intensity of 10^-12 W/m² which corresponds to 0 dB. Among the provided options, (B). 9.90 dB is the closest, hinting at a possible typo in the offered choices.
Step-by-step explanation:
The sound level for a noise that has an intensity of 9.9 x 10^-12 watts/m² can be determined using the formula for sound intensity level in decibels (dB), which is:
β(dB) = 10 × log10(I / I0)
where β is the sound level in decibels, I is the intensity of the sound in watts per meter squared (W/m²), and I0 is the reference sound intensity, which is typically taken as 10^-12 W/m² (the threshold of hearing).
Using this formula:
β = 10 × log10(9.9 x 10^-12 / 10^-12) = 10 × log10(9.9) ≈ 10 × 1 = 10 dB.
However, none of the listed options (8.00 dB, 9.90 dB, 80.00 dB, 99.00 dB) match the calculated sound level of 10 dB. There may be a typo or error within the provided options. If this is the case, then please refer to your teacher or proper guidelines as 9.9 dB is the closest listed option to the calculated value.