# Which Law of Motion Gives the Definition of Force?

Force is defined by Newton’s second law of motion. Using Newton’s second law, a force can affect the motion of a body quantitatively. It asserts that the rate at which a body’s momentum changes is equal to the force exerted on it in both magnitude and direction. In order to calculate a body’s momentum, one must take the product of its mass and velocity into account. Both magnitude and direction are included in the term “momentum,” which is the same as velocity. The direction or magnitude of a body’s momentum can be altered by a force applied to it. The importance of Newton’s second law cannot be overstated in the field of physics. F = ma, where “F” is the force, and “a” is the acceleration, which is both vector numbers, may be written for a body whose mass m is constant. When a net force is exerted on a body, the equation dictates that it accelerates. There is no net force operating on a body that is not accelerated.

As stated by Newton’s third law, when two bodies come into contact, they exert equal-but-opposing-magnitude forces on one another. The third law of thermodynamics, or the law of action and reaction, is often known as the law of conservation of energy. The law of conservation of momentum is a useful tool in the study of static equilibrium when all forces are equal, but it also applies to things in motion. Those pressures are genuine, not just accounting gadgets. An object that is weighted down by its own weight, such as a book on a table, exerts a downward force equal to its own weight. The book is subjected to the same force as the table according to the third law. In order for the book to be held in place, the table has to distort somewhat as a result of its weight. As stated in the second law of motion, every object having net force exerted on it accelerates in accordance. There is no force acting on a body, either because there are no forces or because all forces are properly balanced by opposing forces, and hence the body does not accelerate. Similarly, if a body is observed to not be accelerating, it may be concluded that there is no net force acting on it.

Philosophiae Naturalis Principia Mathematica (1687), also known as the Principia, is where Newton first introduced his laws. He proposed that rather than the Earth, the Sun may be at its center in 1543. Since then, Galileo, Kepler, and Descartes have established the basis for a new science that would both replace the Aristotelian worldview and explain heliocentric universe workings. Newton invented it in the Principia. To explain why the orbits of the planets are ellipses rather than circles, he created his three laws. However, it turned out that he explained far more than he originally intended. The Scientific Revolution refers to the events that took place between Copernicus and Newton. Throughout the 20th century, Newtonian physics was supplanted by quantum mechanics and relativity. In spite of these limitations, Newton’s equations provide a realistic picture of the natural world, except for extremely tiny and fast-moving objects, such as electrons and atoms. Larger bodies and slower motion reduce quantum mechanics and relativity to Newton’s rules.

Here are a few tips that will help you to understand these concepts more properly. Learn the basics of velocity, displacement, and force so that you can grasp these topics.

**Velocity: **Velocity is a measure of the pace at which an object moves in relation to a reference frame. Velocity is a description of an object’s speed and direction of movement. Kinematics is the field of classical mechanics that deals with the motion of bodies, and velocity is a basic notion in kinematics. As a physical vector quantity, velocity is defined by its magnitude and direction. Scalar total velocity is referred to as speed in the SI system, which measures it in meters per second. If “10 meters per second” is written as “10 meters per second west,” then “10 meters per second west” is a vector, not a scalar. The object is considered to be accelerating if it changes speed, direction, or both.

**Do you know the answer of the below question?**

**Displacement:** The smallest distance between the beginning and final positions of a moving point P is the length of a displacement vector in geometry and mechanics.

Net or total motion along a straight line from a point’s beginning location to its ultimate location is quantified in this way. The translation of the original position to the end position can be used to identify a displacement.

**Acceleration: **Acceleration is defined in mechanics as the rate at which the velocity of a moving object changes over time. It is to be noted that vector quantity is an acceleration. It is the net force exerted on an object that determines an object’s acceleration’s angular momentum.