Lecture 16: Collisions - Elastic and Inelastic - Center of Mass Frame of Reference
recorded by: Massachusetts Institute of Technology, MIT
published: Oct. 10, 2008, recorded: October 1999, views: 40961
released under terms of: Creative Commons Attribution Non-Commercial Share Alike (CC-BY-NC-SA)
Download mit801f99_lewin_lec16_01.m4v (Video - generic video source 105.0 MB)
Download mit801f99_lewin_lec16_01.rm (Video - generic video source 106.5 MB)
Download mit801f99_lewin_lec16_01.flv (Video 106.0 MB)
Download mit801f99_lewin_lec16_01_352x240_h264.mp4 (Video 146.3 MB)
Download mit801f99_lewin_lec16_01.wmv (Video 430.7 MB)
Download subtitles: TT/XML, RT, SRT
Report a problem or upload filesIf you have found a problem with this lecture or would like to send us extra material, articles, exercises, etc., please use our ticket system to describe your request and upload the data.
Enter your e-mail into the 'Cc' field, and we will keep you updated with your request's status.
>>PLEASE TAKE A QUICK SURVEY<<
1. 1D Elastic Collisions:
A mass with given speed collides with a second mass (initially at rest) in a one dimensional collision. Momentum is conserved. If kinetic energy is also conserved, the velocities of both objects after the collision can be calculated. Three limiting cases are explored analytically, and then demonstrated. The equations are used to predict the outcome of some air track experiments.
2. Brain Teaser - Elastic Collision with a Wall:
A tennis ball bounces off a wall elastically. The momentum of the wall changes, but the kinetic energy of the wall remains zero. How is that possible? Something to think about!
3. Center of Mass (CM) Frame of Reference:
A 1D elastic collision is considered as seen from the CM frame of reference (where the total momentum is zero). Using the velocity of the CM in the Lab frame, you can transfer between the two frames.
4. 1D Inelastic Collision and Internal Energy:
A 1D inelastic collision is considered from the laboratory and the CM frame. The kinetic energy is calculated in both frames and it is shown that the initial KE in the CM frame is the maximum KE that can be converted to heat (this is called the internal energy of a system). The equations are used to predict the results of an air track experiment.
5. Newton's Cradle Demonstration:
Professor Lewin solicits an analytical proof of his demo showing a lineup of colliding balls.
Link this pageWould you like to put a link to this lecture on your homepage?
Go ahead! Copy the HTML snippet !
Reviews and comments:
Good for Knowlegde..Thankxxxxxx
sir,i wanted to know..what r centre of mass frame of refrence & laboratory frame of refrence? and the difference between the 2?
its wonderful to know something related to the subject in depth...
Whats the answer to this?
A tennis ball bounces off a wall elastically. The momentum of the wall changes, but the kinetic energy of the wall remains zero. How is that possible?
is it just that the wall with infinite mass has KE that approaches zero?
We have translated this entire course for you from English into 11 languages.
Check this video and give us some feedback in this short survey https://www.surveymonkey.co.uk/r/6DMBC3Q
How do I prove the formula of
coefficient of restitution
Write your own review or comment: