The relation with no clock in it
Sometimes nobody timed anything. A braking test gives you a speed and a distance; a chute gives you a drop and an arrival speed. For those, eliminate between the two relations you already have and what survives is — read aloud, v squared equals v-nought squared plus two a d. The cast is unchanged: is the final speed and the starting speed, both in m/s; is the acceleration in ; is the distance in metres over which it acted. No anywhere — that absence is the entire reason it exists.
Everything here is a SQUARED speed, and that is the trap the relation sets. is not ; is not . Square each speed first, do the arithmetic in the currency of , and take the root only at the very end, when you are ready to be handed a speed back.
The engineering payoff is the one every braking chart is built on. Set and the relation becomes : stopping distance grows with the SQUARE of the speed you started at. Twenty per cent faster is forty-four per cent more room. And notice the mass is nowhere in it — it cancelled between and the friction that does the braking, which is why a laden truck and an empty one stop in the same distance at the same deceleration.