[填空题]
(a) Estimate the power outpune *5/lv,cb** ut3q0 zdb m3aazbsdn6t;o3n4f3h w i:on)1lbe6hcwt w of sound from a person speaking in normal conversation. Use Table 12–2. Assume the sound spreads rough1f3h: e b;cw i)n3wno4tw 6lohly uniformly over a sphere centered on the mouth. $\approx$ $ \times10^{ -6}$W(Round to the nearest integer)
(b) How many people would it take to produce a total sound output of 100 W of ordinary conversation? [Hint: Add intensities, not dB’s.]$\approx$ $ \times10^{7}$people
