A converging lens has how many focal points

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 of the following will cause an induced current in a coil of wire? the constant field of the earth passing through the coil a magnet resting near the coil a magnet being moved into or out of the coil a wire carrying a constant current near the coil

Awave is propagating from left to right in a medium. the particles in the medium are also vibrating from left to right. what kind of wave does this describe? a. longitudinal wave b. transverse wave c. mechanical wave d. electromagnetic wave