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).