Acceleration is _______________

An object’s speed in a specific direction

An object’s direction’s rate of change

An object’s velocity’s rate of change

An object’s speed when its motion is constant

An object’s velocity's rate of change

Acceleration is the rate at which an object's velocity changes over time. To determine the acceleration of an object, you need to know its initial velocity, final velocity, and the time it takes to change from the initial velocity to the final velocity. The formula for calculating acceleration is:

Acceleration (a) = (Final velocity - Initial velocity) / Time

So, acceleration is not just the object's speed (magnitude of velocity), but also takes into account its direction. Therefore, out of the given options, the correct definition of acceleration is "An object’s velocity’s rate of change." It represents how quickly an object's velocity changes and in what direction.

Acceleration is the rate at which an object's velocity changes over time. It is the measure of how quickly the speed or direction of an object changes. Therefore, of the options given, the correct answer would be "An object’s velocity’s rate of change".