50 j of work was performed in 20 seconds. how much power was used to do this task? a. 0.4 w b. 2.5 w c. 4 w d. 24.5 w

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

You add 800 ml of water at 20c to 800 ml of water at 80c what is the most likely final temperature of the mixture ? a. 100c b. 60c c. 25 c d.50c

Due in 40 explain in terms of frame of reference if you’re inside a moving train everything on the outside can seem to be moving