If the only force acting on an object is friction during a given physical process, which of the following assumptions must be made in regard to the object's kinetic energy?
a. The kinetic energy decreases.
b. The kinetic energy increases.
C. The kinetic energy remains constant.
d. The kinetic energy decreases and then increases.

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