What quantifies the rate of change of velocity?

Acceleration quantifies the rate of change of velocity. It represents how quickly an object's velocity is changing over time. Specifically, acceleration is defined as the change in velocity divided by the time interval during which that change occurs.

This can be mathematically expressed as:

[ a = \frac{\Delta v}{\Delta t} ]

where ( a ) is acceleration, ( \Delta v ) is the change in velocity, and ( \Delta t ) is the change in time. When an object speeds up, slows down, or changes direction, its velocity is changing, and acceleration provides a measure of how fast that change occurs.

Other concepts in the choices serve different roles. For instance, force relates to an object's mass and its acceleration (Newton's second law), while displacement refers to the change in position of an object, and velocity is simply the speed of an object in a specified direction. Therefore, acceleration is the only option that directly addresses the concept of the rate of change of velocity.