Solve the problem.
-The level of a sound in decibels is calculated using the formula
$$D = 10 \cdot \log \left( I \times 10 ^ { 12 } \right)$$
where $I$ is the intensity of the sound waves in watts per square meter. A electric shaver puts out $0.0001$ watt per square meter. How many decibels is that?
A) $- 40$
B) 8
C) 800
D) 80

Question

Quizplus · Accepted Answer

Using the given formula $D = 10 \cdot \log \left( I \times 10 ^ { 12 } \right)$ and substituting $I = 0.0001$, we get $D = 10 \cdot \log \left( 0.0001 \times 10 ^ { 12 } \right) = 10 \cdot \log \left( 10^8 \right) = 10 \cdot 8 = 80$ decibels.

Solve the Problem D=10⋅log⁡(I×1012)D = 10 \cdot \log \left( I \times 10 ^ { 12 } \right)D=10⋅log(I×1012)

Solve the Problem $D = 10 \cdot \log \left( I \times 10 ^ { 12 } \right)$