I'm working on a project in which I have to build a tiny 4 cm long heater. I did this with copper-windings stuffed in a tiny steel rod. Now I know the power input into this heater is 0.368W, at constant voltage 1.5 volts and the resistance of the heating element is 6.1ohms for a time of 180seconds. I want to know how to calculate the heat pulse (q) generated in this time. What's the formula for doing this? The internet is unclear. Take this at any distance r from the axis.