Velocity and speed are related, but they are not the same thing. Here's how velocity can change while speed remains constant:

* Velocity is a vector: Velocity has both magnitude (speed) and direction.

* Speed is a scalar: Speed only has magnitude.

Example: Imagine a car driving around a circular track at a constant speed of 50 mph.

* Speed is constant: The car's speed remains 50 mph throughout the entire loop.

* Velocity is changing: Even though the car's speed is constant, its velocity is constantly changing because its direction is changing.

In Summary:

To change velocity, you can either:

1. Change speed: Increase or decrease the speed of the object.

2. Change direction: Even if speed stays the same, altering the direction of movement changes the velocity.