A 300mm long piece of 75mm mild steel pipe is placed inside a 300mm long piece of 350mm x 80mm oval aluminium tube. The pipe is heated to 100C and then water at 10 C is pumped into the cavity between the Pipe and tube. Assuming there is ends on the tube the heat loss from the outer wall of the tube is negligible and the pipe continues to be heated to 100C Calculate the time taken to hear the water in the cavity from 10C to 40C. 350mm | 80mm-1 75mm pipe 75mm mild steel pipe with 1.5mm wall thickness Oral aluminum tube. Wall thickness 1-6mm