How is acceleration defined in physics?

Acceleration in physics is defined as the rate of change of velocity over time. This means that it measures how quickly an object's velocity is changing, which can occur in two main ways: an increase in speed (positive acceleration) or a decrease in speed (negative acceleration or deceleration).

Velocity itself is a vector quantity that includes both speed and direction; thus, if either the speed or the direction of an object changes, the velocity changes. By dividing the change in velocity by the time over which that change occurs, you obtain acceleration, which is typically expressed in units such as meters per second squared (m/s²).

This definition plays a key role in kinematics and dynamics, helping to understand the motion of objects in a variety of contexts, from simple free-fall scenarios to complex interactions in systems experiencing forces. Understanding acceleration is crucial for solving problems related to motion, as it links the concepts of force, mass, and motion through Newton's second law of motion.