In physics, a force is any interaction that, when unopposed, will change the motion of an object. ... The original form of Newton's second law states that the net force acting upon an object is equal to the rate at which its momentum changes with time.

Sir Isaac Newton (1643-1727) was an English mathematician, physicist, and astronomer. He is widely regarded as one of the most influential scientists in history and is best known for his laws of motion and universal gravitation.

Newton's laws of motion describe the relationship between the motion of an object and the forces acting upon it. The first law, also known as the law of inertia, states that an object at rest will stay at rest, and an object in motion will stay in motion with the same speed and direction, unless acted upon by an external force. The second law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. The third law states that for every action, there is an equal and opposite reaction.

Newton also formulated the law of universal gravitation, which states that every particle of matter in the universe attracts every other particle with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

In addition to his laws of motion and gravitation, Newton made significant contributions to the field of optics, including the discovery that white light is composed of a spectrum of colors and the invention of the reflecting telescope. He also developed a mathematical method called calculus, which has become an essential tool in many branches of science.

Newton's work laid the foundation for classical mechanics and had a profound impact on the scientific revolution of the 17th century. His laws and principles are still used today to understand and predict the behavior of objects in motion.