[填空题]
(a) Estimate the power output of sound from a person sglmn afyf, 565peaking inc)9+9t w icmtz normal conversation. Use Table 12–2. Assume the sound spreads roughly uniformly )tczc9mti 9+ wover 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
