Newton-second
SI derived unit of impulse
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.
It can be used to identify the resultant velocity of a mass if a force accelerates the mass for a specific time interval.
01Definition
Momentum is given by the formula:
is the momentum in newton-seconds (N⋅s) or "kilogram-metres per second" (kg⋅m/s)
is the mass in kilograms (kg)
is the velocity in metres per second (m/s)
02Examples
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 420-gram (15 oz) football (FIFA specified weight for outdoor size 5) kicked to a speed of 8.6 km/h (5.3 mph). |
| 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 137 km/h (85 mph), making it one of the hardest kicks measured. |
| 1300 | 10 | 13000 | A four-door car weighing 1300 kg (2900 lb) crashing at 36 km/h (22 mph). |
| 2000 | 10 | 20000 | A mid-size SUV weighing 2000 kg (4400 lb) crashing at 36 km/h (22 mph). |
| 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. |
| 132500 | 8050 | 1.07×109 | Space Shuttle launched from Earth to orbit |
| 45702 | 10834 | 4.95×108 | Apollo 11 launched from Earth to orbit |
| 0.0075 | 350 | 2.6 | A 7.5-gram (0.26 oz) handgun bullet (e.g. 9mm Parabellum) fired at 350 m/s (1100 ft/s). |
| 0.004 | 945 | 3.8 | A 4-gram (0.14 oz) rifle bullet (e.g. 5.56×45mm NATO) fired at 945 m/s (3100 ft/s). |
| 0.05 | 860 | 43 | A 50-gram (1.8 oz) anti-material bullet (e.g. .50 BMG) fired at 860 m/s (2800 ft/s). |
Sources and credits
This article is adapted from the Wikipedia article “Newton-second”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- Impuls Masse Geschwindigkeit.svg by Stündle, CC0
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