The toy drive ledger accepts growth only at matching frequency. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Matching frequency opens the coherent ledger

The drive frequency and natural frequency are both 4 hertz, so the match label is yes.

fdrive=fnat=4 Hzf_\mathrm{drive}=f_\mathrm{nat}=4\ \mathrm{Hz}
Matching drive ledgerThe match flag is computed from the two frequencies.f0=4 Hzfdrive=4 HzkickTotal=8 Jaccepted=8 Jmatch=yeskick1=2 Jkick2=2 Jkick3=2 Jkick4=2 J

Four accepted kicks add to eight joules

Four kicks of 2 joules each give accepted growth 8 joules.

42=8 J4\cdot 2=8\ \mathrm{J}
Coherent kick ledgerEach visible kick label is checked.f0=4 Hzfdrive=4 HzkickTotal=8 Jaccepted=8 Jmatch=yeskick1=2 Jkick2=2 Jkick3=2 Jkick4=2 J