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Newton-second

{{Short description|SI derived unit of impulse}}

{{Infobox unit

| bgcolor =

| name = newton-second

| image = File:Impuls Masse Geschwindigkeit.svg

| caption = For objects moving with the same velocity (v), each object's momentum (p) is proportional to its mass (m).

| standard = SI

| quantity = impulse and momentum

| symbol = N⋅s

| namedafter = Isaac Newton

| extralabel = In SI base units:

| extradata = kg⋅m/s

| units1 =

| inunits1 =

}}

The newton-second (also newton second; symbol: N⋅s or N s){{SIbrochure8th}} 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.

:\vec F \cdot t = \Delta m \vec v

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:

:\mathbf{p} = m \mathbf{v},

Examples

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

class="sortable wikitable"
Mass
(kg)

! Speed
(m/s)

! Momentum
(N⋅s)

! Explanation

0.42

| 2.4

| 1

| A {{convert|420|g|adj=on}} football (FIFA specified weight for outdoor size 5) kicked to a speed of {{cvt|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 {{cvt|137|km/h}}, making it one of the hardest kicks measured.

{{val|1300}}

| 10

| {{val|13000}}

| A four-door car weighing {{cvt|1300|kg|comma=gaps}} crashing at {{cvt|36|km/h}}.

{{val|2000}}

| 10

| {{val|20000}}

| A mid-size SUV weighing {{cvt|2000|kg|comma=gaps}} crashing at {{cvt|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.

{{val|132500}}

| {{val|8050}}

| {{val|1.07e9}}

| Space Shuttle launched from Earth to orbit{{efn|Space Shuttle weight here includes the heaviest possible payload (27500 kg), empty external tank (30000 kg), and the shuttle itself (75000 kg) all in a low Earth orbit (8.05 km/s). As the Space Shuttle uses staging, not all launched components reach all the way to orbit (e.g. the boosters). The total impulse gained by all stages together during the launch is {{val|5.7e9}} Ns.}}

{{val|45702}}

| {{val|10834}}

| {{val|4.95e8}}

| Apollo 11 launched from Earth to orbit

0.0075

| 350

| 2.6

| A {{convert|7.5|g|adj=on}} handgun bullet (e.g. 9mm Parabellum) fired at {{cvt|350|m/s|comma=gaps}}.

0.004

| 945

| 3.8

| A {{convert|4|g|adj=on}} rifle bullet (e.g. 5.56×45mm NATO) fired at {{cvt|945|m/s|comma=gaps}}.

0.05

| 860

| 43

| A {{convert|50|g|adj=on}} anti-material bullet (e.g. .50 BMG) fired at {{cvt|860|m/s|comma=gaps}}.

{{notelist}}

See also

References

{{SI units}}

{{DEFAULTSORT:Newton-second}}

Category:Classical mechanics

Category:SI derived units

Category:Units of measurement

{{classicalmechanics-stub}}

{{Measurement-stub}}