Calculate linear momentum and the impulse required to change it.
Momentum change equals force times time, so extending the duration of a collision reduces the peak force proportionally. That is the entire principle behind crumple zones and airbags. A crash that takes twice as long to stop halves the average force on the occupants, which is why stopping distance matters more than speed alone.
Momentum
p = m v; impulse–momentum: F Δt = Δp
p = m v; impulse–momentum: F Δt = Δp Momentum change equals force times time, so extending the duration of a collision reduces the peak force proportionally. That is the entire principle behind crumple zones and airbags.
A crash that takes twice as long to stop halves the average force on the occupants, which is why stopping distance matters more than speed alone.
This calculator takes 4 inputs: Mass, Velocity, Final velocity, Time over which it changes. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.