| newton-second | |
| Standard: | SI |
| Quantity: | impulse and momentum |
| Symbol: | N⋅s |
| Namedafter: | Isaac Newton |
| Extralabel: | In SI base units: |
| Extradata: | kg⋅m/s |
The newton-second (also newton second; symbol: N⋅s or N s) is the unit of impulse in the International System of Units (SI). It is dimensionally equivalent to the momentum unit kilogram-metre per second (kg⋅m/s). One newton-second corresponds to a one-newton force applied for one second.
\vecF ⋅ t=\Deltam\vecv
It can be used to identify the resultant velocity of a mass if a force accelerates the mass for a specific time interval.
Momentum is given by the formula:
p=mv,
p
m
v
This table gives the magnitudes of some momenta for various masses and speeds.
| Mass (kg) | Speed (m/s) | Momentum (N⋅s) | Explanation |
|---|---|---|---|
| 0.42 | 2.4 | 1 | A 420g football (FIFA specified weight for outdoor size 5) kicked to a speed of . |
| 0.42 | 38 | 16 | The momentum of the famous football kick of the Brazilian player Roberto Carlos in the match against France in 1997. The football had a speed of, making it one of the hardest kicks measured. |
| 10 | A four-door car weighing crashing at . | ||
| 10 | A mid-size SUV weighing crashing at . | ||
| 6 | 1 | 6 | The total impulse of a class C model rocket engine, which can be found in amateur fireworks. |
| 10 | 2 | 20 | The total impulse of a class D model rocket engine, which also can be found in amateur fireworks. |
| Space Shuttle launched from Earth to orbit | |||
| Apollo 11 launched from Earth to orbit | |||
| 0.0075 | 350 | 2.6 | A 7.5g handgun bullet (e.g. 9mm Parabellum) fired at . |
| 0.004 | 945 | 3.8 | A 4g rifle bullet (e.g. 5.56×45mm NATO) fired at . |
| 0.05 | 860 | 43 | A 50g anti-material bullet (e.g. .50 BMG) fired at . |