If you did not push the physics book, the book remains still (static) and the net force on the book is zero . Electric current and activity in electric circuits occurs because of a net electric force ...

A force is a push or a pull that acts on an object due to the interaction with another object. Force is measured in newtons (N). Forces are divided into contact forces and non-contact forces.

Join Pat Doyle from Dublin's Institute of Education as he takes students through the Leaving Cert Physics Higher Level exam.