M. Ivanovsky's book "Laws of Motion" introduces readers to the basic laws of mechanics and the history of their discovery. Along with this, it tells about the life and work of the great scientists Aristotle, Galileo and Newton. The book is designed for middle-aged schoolchildren. Due to the sudden death of the author, the manuscript remained unfinished. Work on preparing it for publication was carried out by B.I. Smagin. At the same time, chapters IV, V, VI and VII underwent significant revision. The material of these chapters has been corrected and supplemented with new sections.