g A gamma-ray photon of energy 800 keV scatters off an electron at an angle perpendicular to its original direction. It then scatters off a second electron such that this secondary scattered photon continues in the direction of the original photon. Calculate the energy difference between the initial and final photon.

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