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

This is an AMP page - Open full page! for all features.

Impulse and Impulse Force

Forces acting a very short time are called impulse forces

Sponsored Links

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

F = dM / dt                                      (1)

where

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)

where

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.

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)

where

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

Sponsored Links

Related Topics

Related Documents

Sponsored Links

Share

Search Engineering ToolBox

  • the most efficient way to navigate the Engineering ToolBox!

SketchUp Extension - Online 3D modeling!

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 the amazing, fun and free SketchUp Make and SketchUp Pro .Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!

Topics

Unit Converters

Temperature

oC
oF


Load Calculator!

Length

m
km
in
ft
yards
miles
naut miles


Load Calculator!

Area

m2
km2
in2
ft2
miles2
acres


Load Calculator!

Volume

m3
liters
in3
ft3
us gal


Load Calculator!

Weight

kgf
N
lbf


Load Calculator!

Velocity

m/s
km/h
ft/min
ft/s
mph
knots


Load Calculator!

Pressure

Pa (N/m2)
bar
mm H2O
kg/cm2
psi
inches H2O


Load Calculator!

Flow

m3/s
m3/h
US gpm
cfm


Load Calculator!

8 17