I = 870pie^2a^2f^2 The intensity, I of a sound wave is defined as its power output per unit area and is measured in watts per square meter (w/m^2) A sound wave's intensity can be calculated using the above equation, where a stands for the wave's amplitude in meters (m) and f stands for its frequency of vibration in hertz (Hz). If a particular sound wave has an intensity of 0.05 w/m^2 and an amplitude of 3 x 10^-5 m, which of the following is most nearly its frequency?
a. 8.77 hertz
B
80 hertz
c.6,500 hertz
d. 4 x 107 hertz