A solid material has thermal conductivity K in kilowatts per meter-kelvin and temperature given at each point by w(x, y, z) = 10 5(x2 + y2 + 22) C. Use the fact that heat ow is given by the vector eld F = KVw and the rate of heat ow across a surface 5 Within the solid is given by K rs Vw (15. Find the rate of heat ow out of a sphere of radius 1 (centered at the origin) inside a large cube of copper (K = 400 kW/(m - K)). (Use symbolic notation and fractions where needed.) Incorrect