A flatbed truck is carrying a crate along a level road. The coefficient of static friction between the load and the bed is 0.40. The truck accelerates forward and the crate stays in its place on the truck bed. In what direction is the force that the bed exerts on the crate? a) forwards
b) backwards
c) towards the center of the road
d) there is no frictional force because the crate does not move in respect to the bed
e) not enough info to answer

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