What is the correct definition of force in physics?

In physics, force is defined as mass multiplied by acceleration, which aligns with Newton's second law of motion. This law states that the force acting on an object is equal to the mass of that object multiplied by the acceleration it experiences as a result of that force. This relationship shows how much an object will accelerate when a specific force is applied, with the mass influencing how much the object resists acceleration (inertia).

The other options represent different physical concepts and do not accurately define force. Speed multiplied by distance gives you work or energy under certain contexts, mass divided by volume refers to density, and energy per unit time corresponds to power. These definitions are distinct from the fundamental concept of force in mechanics. Understanding this definition is crucial for analyzing motion and the interactions between objects in physics.