Heat flows through a cylindrical copper bar at the rate of 100 w. a secon bar between the same two temperatures i bar. what is the rate of heat flow through the second bar? 31. hea copper s twice as long and has twice the diameter as the first 32. the thermal conductivities of wood and concrete are 0.2 w/m k and 0.8 w/m k, pectively. suppose your house has 1-inch-thick wood siding on the outside. you would like to replace the wood siding with a concrete exterior wall. what thickness must the concrete have to provide the same insulating value as the wood? explain. 3. a titanium cube at 400 k radiates 50 w of heat. how much heat does the cube radiate if its temperature is increased to 800 k?