Speed vs. Velocity
* Speed: How fast an object is moving. It's a scalar quantity, meaning it only has magnitude (like 25 mph).
* Velocity: How fast an object is moving *and* in what direction. It's a vector quantity, meaning it has both magnitude and direction (like 25 mph due north).
The Key Difference
An object can have a constant speed but a changing velocity if its direction of motion changes.
Example
Imagine a car driving around a circular track at a steady 60 mph. Here's what's happening:
* Speed: The car's speed is constant at 60 mph.
* Velocity: The car's velocity is constantly changing. Even though the speed is constant, the car's direction is constantly changing as it circles the track.
Other Examples
* A satellite orbiting Earth: It has a constant speed but its velocity is changing because its direction is constantly changing.
* A ball thrown in the air: Its speed slows down as it goes up, and then speeds up as it falls back down. Even though speed is changing, the velocity is changing even more because the ball's direction is changing.
In summary
An object can have a constant speed but a changing velocity if its direction of motion changes. This happens in situations where the object is moving along a curved path or changing its direction.
