How is force defined in physics?

In physics, force is defined as an interaction that can change the motion of an object. This definition captures the essential nature of force, which is not just about calculation, but about the impact it has on motion. When one object interacts with another, the resulting force can cause the object to accelerate, decelerate, or change direction, illustrating the fundamental relationship between force and motion outlined in Newton's laws.

Force is measured in Newtons (N), which is the standard unit within the International System of Units (SI). This unit reflects the amount of force needed to accelerate a 1-kilogram mass by 1 meter per second squared. Understanding force as an interaction helps in comprehending various physical phenomena, ranging from everyday experiences—like pushing a shopping cart—to more complex systems in engineering and physics.

While mass times acceleration is a specific formula for calculating force (Newton's second law), the broader conceptual understanding encompasses interactions as a definition. Other definitions provided do not adequately encompass the comprehensive nature of force; for instance, simply saying it is energy or a mathematical relationship involving velocity does not address its functional role in motion and dynamics.