Calculate impulse from force and time, and the velocity change it produces.
The same impulse can be delivered by a large force briefly or a small force for longer. Since injury depends on force rather than impulse, extending the time is the whole design goal of protective equipment. Doubling the stopping time halves the force for an identical change in momentum, which is why padding and progressive crush structures work.
Impulse
J = F Δt = Δp = m Δv
J = F Δt = Δp = m Δv The same impulse can be delivered by a large force briefly or a small force for longer. Since injury depends on force rather than impulse, extending the time is the whole design goal of protective equipment.
Doubling the stopping time halves the force for an identical change in momentum, which is why padding and progressive crush structures work.
This calculator takes 3 inputs: Average force, Duration of the force, Mass. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.