Speed
* Definition: How fast an object is moving.
* Measurement: Distance traveled per unit of time (e.g., miles per hour, meters per second).
* Scalar Quantity: Only has magnitude (size).
* Example: A car traveling at 60 mph.
Velocity
* Definition: How fast an object is moving *and* in what direction.
* Measurement: Distance traveled per unit of time *and* direction (e.g., 60 mph north, 10 meters per second east).
* Vector Quantity: Has both magnitude and direction.
* Example: A car traveling 60 mph north.
Illustrative Examples:
1. Two Cars on a Track: Imagine two cars on a racetrack. Car A goes around the track once in 1 minute, while Car B goes around twice in the same time. Both cars have the *same average speed* (the distance traveled divided by time). However, they have *different velocities* because they are traveling in different directions.
2. A Ball Thrown Straight Up: A ball thrown straight up slows down as it goes up and speeds up as it comes down. While its speed is changing, its *velocity* changes because the direction of motion is reversed (upward vs. downward).
In Summary:
* Speed is how fast something is moving.
* Velocity is how fast something is moving *and* in what direction.
Think of it this way: Speed tells you how much ground you cover, while velocity tells you where you're going.
