Final answer:
Velocity changing at a uniform rate refers to an object's motion where its velocity is increasing or decreasing by the same amount in equal time intervals. This occurs when the acceleration of the object is constant.
Step-by-step explanation:
In physics, when we talk about velocity changing at a uniform rate, we are referring to an object's motion where its velocity is increasing or decreasing by the same amount in equal time intervals.
For example, if a car is moving at a constant velocity of 40 km/h and then starts accelerating at a constant rate of 10 km/h every second, its velocity is changing at a uniform rate.
Uniform acceleration occurs when the rate of change of velocity with time remains constant. In other words, if the acceleration of an object is constant, then its velocity changes at a uniform rate.