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Android iOS Windows MacOS
with best with Chrome Chrome Chrome Chrome
support fullscreen? Yes. Chrome/Opera No. Firefox/ Sumsung Internet Not yet Yes Yes
cannot work on some mobile browser that don't understand JavaScript such as..... cannot work on Internet Explorer 9 and below



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      Momentum One Dimension Collision Model

The motion of a body of mass m and velocity v is described by a vector quantity known as momentum p where

p = m v

 When objects collide, whether trains, cars, billiard balls, shopping carts, or your foot and the sidewalk, the results can be complicated. Yet even in the most chaotic of collisions, as long as there are no net external forces acting on the colliding objects, one principle always holds and provides an excellent tool for understanding the collision. That principle is called the conservation of linear momentum which states that

The total momentum of a system remains constant provided that no external resultant force acts on the system

For two bodies colliding linearly, it is written mathematically as a vector equation

Total initial momentum = total final momentum

m1.u1 + m2.u2 = m1.v1 + m2.v2

If external forces (such as friction) are ignored, the total momentum of two carts prior to a collision (left side of equation) is the same as the total momentum of the carts after the collision (right side of equation).

Collisions are classified into elastic (or perfectly elastic), inelastic and completely inelastic.

There is also a concept of kinetic energy of a moving body is stated mathematically by the following equation:

KE1 = ½ m1.v12

Main Simulation View
The simulation has 2 collision carts on frictionless floor and wheels.

Explore the sliders allows varying the variables .

   * mass of cart ONE, mass_1, m1 in kg
   * initial velocity of cart ONE, u1 in m/s
   * mass of cart TWO, mass_2, m2 in kg
   * initial velocity of cart TWO, u2 in m/s

DropDown Menu
Allows for selecting what kind of collision is simulated.

A Perfectly elastic collision is defined as one in which both conservation of momentum and conservation of kinetic energy are observed
A Perfectly Inelastic collision is defined as one in which conservation of momentum is observed but the colliding carts stick together after collision with kinetic energy loss

DropDown Menu
show: velocity, for visualizing the velocity vector
plot momentum vs time graph, for different representation of data for momentum of cart 1, 2 and both.
plot kinetic energy vs time graph, for different representation of data for kinetic energy of cart 1, 2 and both.
hint: COM, for the equation of conservation of momentum
hint: COKE, or the equation of conservation of kinetic energy

Step Forward
have their usual meaning.

The Momentum 1D JavaScript Collision model was created by created by lookang using the Easy Java Simulations (EJS) version 5.2 authoring and modeling tool. Shout our thanks to the Ejs community namely, Francisco Esquembre, Félix J. García Clemente , Fu-Kwun Hwang and Wolfgang Christian for their professional learning community support. You can examine and modify this compiled EJS model if you run the model (double click on the model's jar file), right-click within a plot, and select "Open EJS Model" from the pop-up menu. You must, of course, have EJS installed on your computer. Information about EJS is available at: and in the OSP comPADRE collection  


 Astro Academy: Principia - Collisions by National Space Academy


 Ejs open source java applet 1D collision carts Elastic and Inelastic Collision by lookang lawrence wee

 Ejs open source java applet 1D collision carts Elastic and Inelastic Collision v2 by lookang lawrence wee



  1. JavaScript version of EJSS One Dimension Collision JS Model by 
  2. Java version of the Ejs Open Source Collision Carts Model with AJC and RVHS
  3. Java version of simulation on Digital Library


  1. arXiv:1204.4964 [pdfother]
    One-dimensional collision carts computer model and its design ideas for productive experiential learning
    Comments: 6 pages, 8 figures, 1 table, 1 L. K. Wee, Physics Education 47 (3), 301 (2012); ISSN 0031-9120
    Journal-ref: Physics Education, 47(3), 301 (2012)
    Subjects: Physics Education (physics.ed-ph); Classical Physics (physics.class-ph); Computational Physics (physics.comp-ph)

Other Resources

  1. Collision Carts by Walter Fendt
  2. Collision Carts by Physicsclassroom
  3. EJSS collision model by Dave Lommen
  4. EJS 1D collision model with virtual spring model by Fu-Kwun Hwang and Loo Kang Wee
  5.  Collision Lab by PhET
  7. International Space Station: Collisions Video Analysis with Tracker by Tim Peake, Robin Mobbs, Anu Ojha, Andy McMurry, and Sophie Allan 

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