Question

What is the intensity of the sound from a hairdryer if its decibel level is measured at 60 dB? Choose the correct answer in scientific notation:

a) (6 × 10⁻⁶)
b) (6 × 10⁻⁷)
c) (6 × 10⁻⁹)
d) (6 × 10⁻¹²)

Answer 1

The intensity of the sound from a hairdryer measured at 60 dB, when calculated and displayed in scientific notation, is (6 × 10^-6) W/m².

Step-by-step explanation:

The question asks for the intensity of the sound from a hairdryer measured at 60 dB in scientific notation.

The intensity level in decibels (dB) can be converted to intensity in watts per meter squared (W/m²) using the formula:

I = I0 * 10^(L/10)

where I0 is the reference intensity of 1×10-12 W/m² (the quietest sound a person can hear), and L is the sound intensity level in decibels (dB).

Therefore, we calculate the intensity (I) for 60 dB:

I = 1×10-12 W/m² * 10^(60/10)

I = 1×10-12 W/m² * 106

I = 1×10-6 W/m²

When written in scientific notation, the correct answer is (a) (6 × 10-6 W/m²).