Reg Edwards wrote:
I've lost the original question.

But there is a lossless transmission line 1 second long.
With a velocity factor of 1.0 it is 30,000 kilometres long.

Let Zo = 100 ohms.
Let applied volts = 100 VDC.
Let terminating resistance be 100 ohms.

Line Inductance = 10,000 Henrys.
Line Capacitance = 1 Farad.

Under steady state conditions -
Line current = 1 amp.
Energy stored in inductance = Sqr(I)*L/2 = 5000 Joules.

Volts across capacitance = 100 volts.
Energy stored in capacitance = SqrV)*C/2 = 5000 Joules.

Total energy stored = 10, 000 Joules = 10,000 watt.seconds.

Which has nothing whatsoever to do with all this nonsense about
reflections. Note that energy in inductance equals energy in
capacitance.

Yep, you don't have to mess with those pesky reflections when the line
is terminated in a load equal to its characteristic impedance. Then the
problem reduces to the trivial one you've posed. Simple problem, simple
solution.

Roy Lewallen, W7EL