What is the power dissipated in resistor r3.

Which is not a source of noise pollution? a)airplanes b)acid rain c)machines d)cars

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

Which scientist was the first to propose the heliocentric model of the universe? a. aristotle b. isaac newton c. galileo galilei d. nicolaus copernicus