To clarify the terminology, velocity refers to both speed and direction of motion, whereas speed only represents the magnitude of the velocity. When we say "constant velocity," it means the car is moving at a steady speed in a straight line, without any changes in speed or direction. When we say "constant speed," it means the car is moving at a consistent speed but may change direction.
Now, addressing your question, a car can accelerate while traveling at a constant speed but not at constant velocity because acceleration is a change in velocity, not just speed. Acceleration occurs when there is a change in either speed or direction or both.
When a car is moving at a constant speed in a straight line (constant velocity), it maintains the same speed and direction. Since acceleration is defined as a change in velocity, there is no acceleration happening when the car maintains a constant velocity.
However, even when the car is traveling at a constant speed, it can still accelerate if there's a change in its direction. This acceleration is called centripetal acceleration, and it occurs when the car turns or changes its path. The car's velocity is changing due to its direction changing, even though its speed remains constant.
On the other hand, when a car accelerates while moving at a constant speed, it means there is a change in its speed. This acceleration is known as linear acceleration. It happens when the car's speed increases or decreases while it continues to move in the same direction.
In summary, a car can accelerate while traveling at a constant speed if it changes direction, resulting in centripetal acceleration. Additionally, a car can also accelerate while moving at a constant velocity if its speed changes, leading to linear acceleration.