newton second | |
---|---|

General information | |

Unit system | SI derived unit |

Unit of | Impulse and momentum |

Symbol | N s |

Named after | Isaac Newton |

In SI base units: | kg ⋅ m/s |

The **newton second** (also **newton-second**, symbol **N s** or **N·s**)^{[1]} is the derived SI unit of impulse. 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.

## Contents

## Definition[edit]

Momentum is given by the formula:

- is the momentum in newton second (N s) or "kilogram meters per second" (kg·m/s)
- is the mass in kilogram
- is the velocity in meters per second (m/s)

- N s = N s= kg m/s

## Examples[edit]

This table gives the magnitudes of some momenta for various masses and speeds.

Mass (kg) | Speed (m/s) | Momentum newton seconds | Explanation |
---|---|---|---|

0.42 | 2.4 | 1 | A 420 gram football (FIFA specified weight for outdoor size 5) kicked to a speed of 8.6 km/h. |

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, making it one of the hardest kicks measured. |

1,500 | 10 | 15,000 | A regular small car weighing 1.5 tons crashing at 36 km/h |

2,600 | 10 | 26,000 | An SUV weighing 2.6 t (2.6 Mg) crashing at 36 km/h |

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. |

2,030,000 | 8050 | 1.63x10^{10} | Space Shuttle launched from earth to orbit |

45,702 | 10834 | 4.95x10^{8} | Apollo 11 launched from earth to orbit |

0.0075 | 350 | 2.6 | 9x19 mm 7.5 gram pistol round launched at 350 m/s |

0.004 | 945 | 3.8 | 5.56 mm (0.223) 4 gram rifle round launched at 945 m/s |

0.05 | 860 | 43 | 12.7x99 mm (0.50 BMG) 50 gram rifle round launched at 860 m/s |

## See also[edit]

- Power factor
- Newton meter, the derived SI unit of torque
- Orders of magnitude (momentum), for examples of momenta

## References[edit]

**^**International Bureau of Weights and Measures (2006),*The International System of Units (SI)*(PDF) (8th ed.), ISBN 92-822-2213-6, archived (PDF) from the original on 2017-08-14

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