If a projectile is fired straight up at a speed of 30 m/s, the total time to return to its starting point is about * A. 5 points
B.3 seconds.
C.6 seconds.
D.30 seconds.
E.60 seconds.
F. not enough information to estimate

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