{"type":"rich","version":"1.0","title":"Gravitational potential energy between a point mass and a system of many point masses","html":"<span class=\"wb-embed wb-embed-math\" data-latex=\"U(\\mathbf{r})=-Gm\\sum_i \\frac{M_i}{\\mathbf{r}-\\mathbf{r}_i}\">U(\\mathbf{r})=-Gm\\sum_i \\frac{M_i}{\\mathbf{r}-\\mathbf{r}_i}</span><footer><cite class=\"wb-embed-author\">Rong Martin-Siebler ZHOU</cite></footer>","width":640,"height":320}