Apipe of outside diameter 200 mm is lagged with an insulating material of thermal conductivity 0.06 w m k-1 and thickness 75 mm. the pipe carries a process fluid at a temperature of 300 °c and the average temperature of the outer surface of the lagging is 45 °c (a) estimate the rate of heat loss per metre length of pipe. (b) explain why the thermal resistance of the pipe wall can be ignored.

Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. the astronaut has her lucky penny in her hand behind her back as the space pirates break into the control room. she has just locked the controls so that the ship is accelerating in the direction of the control room’s ceiling. simon wants the astronaut to use the penny to hit a button on the control panel to turn off the lights and escape. the button is located a short distance behind and below the astronaut’s hands. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?