3. a 40.0-kg wagon is towed up a hill inclined at 18.5 with respect to the horizontal. the tow rope is parallel to the incline and has a tension of 140 n. assume that the wagon starts from rest at the bottom of the hill, and neglect friction. how fast is the wagon going after moving 80.0 m up the hill?

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