Apoint source emits 28.9 w of sound isotropically. a small microphone intercepts the sound in an area of 0.214 cm2, 390 m from the source. calculate (a) the sound intensity there and (b) the power intercepted by the microphone.

Beryl states that insulation with the smallest possible thermal conductivity is best to keep a house warm in winter, but worst for keeping a house cool in summer. sapphire insists the reverse is true: low thermal conductivity is good in the summer, but bad in the winter. which one, if either is correct? a. beryl, because low thermal conductivity results in low heat transfer. b. beryl, because low thermal conductivity results in high heat transfer. d. sapphire, because low thermal conductivity results in high heat transfer. e. neither, because low heat transfer is desirable both in summer and in winter.