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:
Definition Momentum is given by the formula
where
Examples 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 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 handgun bullet (e.g. 9mm Parabellum) fired at . 0.004 945 3.8 A rifle bullet (e.g. 5.56×45mm NATO) fired at . 0.05 860 43 A anti-material bullet (e.g. .50 BMG) fired at .
See also Power factor Newton-metre – SI unit of torque Orders of magnitude (momentum) – examples of momenta
References