The book, along with the usually considered issues, pays special attention to the movement of charged particles in electric and magnetic fields. This allows not only to expand the range of physical phenomena that are involved in illustrating the problems of mechanics, but also allows to organically introduce into mechanics an exposition of the foundations of the special theory of relativity. This construction of the book is a pedagogically justified innovation. Compared to the first edition, published in 1962, the book has made separate clarifications and small additions.