What is defined as a change in speed without a change in direction?

The concept of linear acceleration is defined as a change in speed without a change in direction. This means that while an object's velocity is increasing or decreasing, the trajectory or path it follows remains constant.

In physics, acceleration refers to any change in velocity, which encompasses both changes in speed and changes in direction. When only the speed changes while the direction remains the same, this is specifically categorized as linear acceleration. This is often observed in scenarios where an object moves in a straight line and either speeds up or slows down.

For instance, when a car accelerates from a stop to a higher speed on a straight road, its direction remains unchanged, fulfilling the criteria for linear acceleration. Understanding this definition is crucial in the study of motion and dynamics, as it allows one to analyze and predict the behavior of objects in motion more accurately.