The purpose of this wiki is to provide articles on physics concepts as well as provide everyone from physics graduate students to casual readers with peer-reviewed problems and solutions. Many of these problems are graduate-level, from public problem banks. Public problem banks are often compiled by various university physics departments and include questions that they have given on previous PhD qualifying/prelim exams. The community can submit problems, search for problems, and post or correct solutions to these problems.
Gravity is one of the four fundamental forces. It is the weakest of the four forces, yet one of the most easily observed. It causes a mutual attraction between two bodies by virtue of their masses. Gravitational force is believed to be caused by the exchange of yet to be discovered particles called gravitons. Read More