The brick wall (of thermal conductivity 0.77 W/m · ◦ C) of a building has dimensions of 3 m by 15 m and is 7 cm thick. How much heat flows through the wall in a 8.4 h period when the average inside and outside temperatures are, respectively, 29◦C and 5◦C? Answer in units of MJ.

What is the length x of the side of the triangle below? (hint: use the cosine function)

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

Total solidification times of three casting geometries are to be compared: a sphere, a cylinder, in which the length-to-diameter ration - 1.0, and a cube. volume = 1000 cm^3 for all three shhapes, and the same casting alloy is used. a) determine the solidification times of each geometry b) based on the results of part (a), which geometric element would make the best riser? c) if the mold constant = 3.5 min/cm^2 in chvorinov's rule, compute the total solidification time for each casting.