Imagine two nodes, which are connected with a certain unknown conductivity. One node has a fixed temperature of 30 degrees Celsius. The other node has a initial temperature of 80 degrees Celsius. This means that this node is cooling down. The node is after t seconds cooled down to a certain temperature but it hasnt reached Steady State yet. The tau time is determined from this cooling down.
How can I derive the heat capacity from the second node by using these known parameters?