Definition of the acceleration of gravity by means of mathematical and physical pendulums . Laboratory work No. 20 on mechanics” from the team of authors is an indispensable source of knowledge for students, teachers and everyone who is interested in the fundamental laws of nature and the practical methods of their research. This book is a deep and simultaneously accessible guide to conducting laboratory experiments, revealing the secrets of gravity through fascinating experiments with pendulums. The book focuses on a methodology for determining the acceleration of free fall, which has long occupied an important place in training courses in mechanics. The authors masterfully explain how with the help of mathematical and physical pendulums it is possible not only to confirm theoretical positions, but also to obtain practical skills for conducting experiments. The book describes in detail the stages of preparation, conduct and analysis of the results of laboratory work, which makes it a valuable tool for students of technical and natural sciences specialties. Especially interesting is that the authors are not limited to dry formulas: they show how experimental data turn into accurate numerical indicators, and explain why pendulums are one of the most reliable tools for measuring gravity. This book is suitable for students enrolled in courses in physics, mechanics and engineering disciplines, as well as for teachers looking for modern and understandable teaching methods. It will be interesting for those who like to experiment, explore nature and get practical experience in the laboratory. At the age of 16 years and older, readers will find here not only theoretical foundations, but also real instructions on how to conduct an experiment on their own or in the classroom. The topics raised in the book cover a wide range of issues related to pendulum motion, oscillation patterns, and methods for accurately measuring free fall acceleration. The authors emphasize the importance of accuracy and accuracy in laboratory work, which makes the book not only a textbook, but also a kind of guide to the world of experimental physics. Special attention is paid to mathematical modeling and physical aspects, which allows the reader to understand how theoretical knowledge is embodied in practical measurements. The style of presentation is distinguished by clarity and logical consistency, which facilitates the assimilation of complex concepts even for beginners. The authors use live language, avoiding excessive academic rigor, which makes the book attractive to a wide range of readers. In addition, the book contains illustrations, diagrams and examples of calculations, which contributes to a deeper understanding of the material and the development of analytical thinking skills. If you are already familiar with classic textbooks on mechanics or are looking for a modern practical guide to laboratory work, this book will be an excellent assistant for you. It can be compared with popular manuals on experimental physics and laboratory techniques. but the feature of "Definitions of acceleration of gravity by means of mathematical and physical pendulums" is a combination of theory and practice , supported by specific recommendations and examples from real laboratory work. The author’s team created not just a textbook, but a real guide to the world of physical experiments, which will help to understand how the laws of nature work in practice. This book deserves the attention of those who want not only to memorize the formulas, but also to learn how to apply them in real conditions, as well as to develop analytical skills and an experimental approach to the study of physics. As a result of reading, you will gain not only theoretical knowledge, but also confidence in your practical skills, which is especially important for future engineers, scientists and teachers. In General, "Definition of acceleration of gravity by means of mathematical and physical pendulums . Laboratory work No. 20 on mechanics is not just a textbook, but a full-fledged tool for mastering one of the most important topics in mechanics, which will inspire you to new discoveries and help you understand how science turns into practical knowledge.