Antti entered a 10-kilometer race. his goal is to finish in one hour. he starts off sprinting, and completes the first 2 kilometers of the race at an average speed of 12 kilometers per hour. to achieve his goal of a one-hour finish time, what average speed must antti maintain for the last 8 kilometers of the race? enter your answer as a number in decimal form, without units.

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