Simulation elastic and inelastic collisions

This example shows how to modeling elastic and inelastic collisions between two sliders on air track using Simulink Simscape

One important consequence of Newton’s third law is the conservation of momentum in collisions between two bodies. One way of verifying this is to investigate collisions between two sliders on an air track. When all of the kinetic energy is conserved, we speak of elastic collisions. In cases where kinetic energy is only conserved for the common centre of gravity of the two bodies, we use the term inelastic collisions. In this experiment, the individual velocities of the sliders are determined from the times that photoelectric light barriers are interrupted and the momentum values are calculated from these speeds.
Using the track itself as the frame of reference, conservation of momentum is described by the following equation:

p_1+p_2=p_1^'+p_2^'=p=const
p_1,p_2:individual momenta before collision
p_1^',p_2^':individual momenta before collision

Therefore the conservation of momentum is given by:

p=m_1∙v_1=m_1∙v_1^'+m_2∙v_2^'

Here v'1 and v'2 have different values after an elastic collision, but are the same subsequent to an inelastic collision. In an elastic collision, a flat buffer on the first slider collides with a stretched rubber band on the second slider. An inelastic collision involves a long pointed spike being pushed into some modelling clay. The masses of the sliders can be modified by adding weights.

The instantaneous velocity is given by the following:

v=∆s/∆t

In order to measure the instantaneous velocity in this experiment, an interrupter flag of known width Δs is attached to the slider and breaks the beam of a photoelectric sensor as the slider passes by it. The time the beam is broken Δt is measured by means of a digital counter.

Official web-site: http://www.virtlabs.tech

Paid Version (Google Play): https://play.google.com/store/apps/details?id=com.virtlab.laws_of_collisions_full

Free Version (Google Play): https://play.google.com/store/apps/details?id=com.virtlab.laws_of_collisions_demo

Free online-version (HTML5):
http://virtlabs.tech/apps/mechanics/03_demo/simulator.html

Virtual Lab: Laws of Collisions:
https://youtu.be/U8sHAgAVNvY