The article comprehensively highlights the significant contribution of the Italian scholar Galileo Galilei to the history of the development of physics. Galileo Galilei was an Italian philosopher, physicist, and astronomer who exerted a profound influence on the science of his era. Galilei is primarily renowned for his research in the fields of planets and stars, his active support of the heliocentric system of the world, and his experiments in mechanics. The main focus is directed toward the fact that through the experiments conducted by Galileo Galilei, fundamental data and principles regarding the field of mechanics were discovered. During his academic career at the University of Padua, Galilei investigated inertia and the free fall of bodies. By determining that the acceleration of free fall is independent of the mass of a body, he disproved the theory—which had prevailed since the time of Aristotle—stating that the "speed of fall" is proportional to the weight of the body. Galilei verified this by dropping objects of various masses from the top of the Leaning Tower of Pisa to analyze their descent.Furthermore, Galilei is considered one of the founders of the principle of relativity in classical mechanics, which was subsequently named after him. In 1593, Galileo Galilei published a book titled "Mechanics", wherein he extensively detailed his research. Among the phenomena occurring in the universe surrounding us, different forms of motion interested Galilei the most. This holds vital importance in shaping project-based activities among youth, enabling them to independently determine the information they require, facilitating their visualization of the scientific picture of the world, and upbringing a well-rounded generation equipped with the personal intellectual qualities necessary for society.