Speed-square moves specific energy through bound, escape, and unbound rows. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Total specific energy -2

At radius four, potential stays negative four. Speed-square 4 gives kinetic 2 and total -2.

24=22\mathbin{-}4=-2
Energy row 1The energy check cites the same gravity source.speedSquared=4 m^2/s^2kineticSpecific=2 J/kgpotentialSpecific=-4 J/kgtotalSpecificEnergy=-2 J/kgenergyStatus=bound

Total specific energy 0

At radius four, potential stays negative four. Speed-square 8 gives kinetic 4 and total 0.

44=04\mathbin{-}4=0
Energy row 2The energy check cites the same gravity source.speedSquared=8 m^2/s^2kineticSpecific=4 J/kgpotentialSpecific=-4 J/kgtotalSpecificEnergy=0 J/kgenergyStatus=escape

Total specific energy 1

At radius four, potential stays negative four. Speed-square 10 gives kinetic 5 and total 1.

54=15\mathbin{-}4=1
Energy row 3The energy check cites the same gravity source.speedSquared=10 m^2/s^2kineticSpecific=5 J/kgpotentialSpecific=-4 J/kgtotalSpecificEnergy=1 J/kgenergyStatus=unbound

Specific-energy sign separates bound, escape, and unbound

Kinetic energy rises with speed-square while the potential term stays fixed. Negative, zero, and positive totals mark the three statuses.

vvKUϵ4242844010541\begin{array}{c|c|c|c}v\cdot v&K&U&\epsilon\\4&2&-4&-2\\8&4&-4&0\\10&5&-4&1\\\end{array}
Specific-energy sign cross-scanThe displayed middle row is the escape boundary.speedSquared=8 m^2/s^2kineticSpecific=4 J/kgpotentialSpecific=-4 J/kgtotalSpecificEnergy=0 J/kgenergyStatus=escape