A guitar amplifier during a solo at a rock concert produces sound with a power of 40 W. Assume that the sound waves emit and spread spherically. A) What is the intensity of the sound waves as they reach a fan in the front row 16 meters from the amplifier?

B) What about in the back, 53 meters away?

Acarpenter builds an exterior house wall with a layer of wood 2.9 cm thick on the outside and a layer of styrofoam insulation 2.3 cm thick on the inside wall surface. the wood has k=0.080w/(m⋅k), and the styrofoam has k= 0.010 w/(m⋅k). the interior surface temperature is 19.0 ∘c , and the exterior surface temperature is -15.0 ∘c . a.)what is the temperature at the plane where the wood meets the styrofoam? celsius b.)what is the rate of heat flow per square meter through this wall? /m^2