Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Impulse and Impulse Force

Forces acting a very short time are called impulse forces.

According to Newton's Second Law of Motion - force can be expressed as

F = dM / dt                                      (1)


F = applied force (N, lbf)

dM = change of momentum (kg m/s, lb ft/s)

dt = time taken (s)

Eq. (1) can alternatively be expressed as

  dM = F dt                                      (1b)

Change in momentum is force times acting time.

Forces that act for a very short time are called impulse forces. The product of the impulsive force and the time it acts is called the impulse. The impulse is equal to the change of momentum caused by the impulsive force and can be expressed as

I = F dt = dM                                      (2)


I = impulse (N s)

Example - resulting Velocity after an Acting Force

A force 1000 N is acting on a car with mass 1000 kg in 10 second.

Car - acting force and acceleration

The impulse - or change in momentum - can be calculated

I = dM = (1000 N) (10 s)

  = 10000 (N s, kg m/s)

Since momentum can be expressed as

M = m v                                                 (3)


M = momentum (kg m/s, lb ft/s)

m = mass (kg, lb)

v = velocity (m/s, ft/s)

then the velocity of the car after 10 s can be calculated as

v = (10000 kg m/s) / (1000 kg)

 = 10 m/s

 = 36 km/h

Related Topics

  • Dynamics

    Motion of bodies and the action of forces in producing or changing their motion - velocity and acceleration, forces and torque.
  • Mechanics

    The relationships between forces, acceleration, displacement, vectors, motion, momentum, energy of objects and more.

Related Documents


Search is the most efficient way to navigate the Engineering ToolBox.

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

Translate this Page

Translate this page to Your Own Language .

About the Engineering ToolBox!

Privacy Policy

We don't collect information from our users. More about

We use a third-party to provide monetization technologies for our site. You can review their privacy and cookie policy here.

You can change your privacy settings by clicking the following button: .


This page can be cited as

  • The Engineering ToolBox (2008). Impulse and Impulse Force. [online] Available at: [Accessed Day Month Year].

Modify the access date according your visit.

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Unit Converter