The newton-second (also newton second; symbol: N⋅s or N s)^[1] 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.

${\displaystyle {\vec {F}}\cdot t=\Delta m{\vec {v}}}$

It can be used to identify the resultant velocity of a mass if a force accelerates the mass for a specific time interval.

Momentum is given by the formula:

${\displaystyle \mathbf {p} =m\mathbf {v} ,}$

• ${\displaystyle \mathbf {p} }$ is the momentum in newton-seconds (N⋅s) or "kilogram-metres per second" (kg⋅m/s)
• ${\displaystyle m}$ is the mass in kilograms (kg)
• ${\displaystyle \mathbf {v} }$ is the velocity in metres per second (m/s)

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

• Power factor
• Newton-metre – SI unit of torque
• Orders of magnitude (momentum) – examples of momenta