A rod of constant cross-sectional area has conductivity κ1, and conducts heat at a constant rate between two reservoirs held at T1andT2respectively. It takest1= 11.8-s to conductQ= 32.8-J of heat across the rod. How much time would it take to conduct the same amount of heat if half the length of the rod were replaced with a material with conductivity κ2=n·κ1, wheren= 4.2?