Physics is all around us in our daily lives, it’s the reason things…are the way they are. The reason we get from point A to point B and exist on this Earth the way we do. And yet some people don’t buy it, and it drives certain professors to use this demonstration:
While entertaining, it really is true. Ui+Ki=Uf+Kf…barring any external work being done. Conservation of energy at its finest…but it extends far beyond the scope of what we think about in our daily lives; conservation laws lie at the core of our existence. Why does the Earth orbit the sun in the way that it does? Conservation of angular momentum (or L=Iw…the mvr simplification in the book is only for a point mass).
Michael's Astronomy Blog 
This is a very nice summary of the equation in real life. However, I am pleased to say that there is another video of “physics in motion” where one young boy is not so fortunate. After the ball comes back but doesn’t hit him, he forgets about the ball entirely (and all its kinetic energy it still has) and walks towards (presumably) his seat. On the way there, the ball hits him in the stomach! Have you seen this version Michael?
LikeLike
I really like the demonstration video, it does a great job of showing an actual example of the law of conservation. However, are there other examples that we can see this happen? Also, are there other scenarios where this law might not apply?
LikeLike