Impulse of a Force
Impulse of a Force
Impulse — force times the time it acts — equals the change in momentum, the key to understanding impacts and cushioning.
The impulse is J = F·t. where F is the force and t the time it acts.
Inputs
F := 500 N=500 N
t := 0.2 s=0.2 s
Multiply force by time.
J := F·t=100 kg·m/s
Results
For a given momentum change, spreading it over a longer time lowers the force — exactly how airbags and crumple zones reduce injury.
Assumptions & limitations
- Constant force.
- Along one direction.
- Impulse equals momentum change.