N·s
newton second
Momentumexact by definition
The newton second is the SI unit of impulse, one newton applied for one second. It is exactly equal to the kilogram metre per second, because the impulse-momentum theorem says a force acting over a time produces precisely that change in momentum. The two names describe the same unit from opposite ends of the same equation.
Watch out: Rocket motor total impulse is quoted in newton seconds and is not the same as thrust, which is in newtons. A motor with 1000 N of thrust for 5 s delivers 5000 N·s of impulse, and a motor with 500 N for 10 s delivers the same impulse while accelerating the vehicle differently.
| 1 N·s | 1 kg·m/s |
Solvers that use momentum