Mirror impulse is checked through doubled pressure and force over time. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Mirror impulse comes from doubled pressure
The mirror path is checked through pressure, force, and time.
Jmirror=Ft=6⋅4=24kgm/s
The absorber momentum equality is off
The mirror lesson leaves the absorber momentum closure disabled.