Acceleration is about *change* in velocity, not just speed.
* Speed is how fast an object is moving. It's a scalar quantity, meaning it only has magnitude (e.g., 20 mph).
* Velocity is speed with a direction. It's a vector quantity (e.g., 20 mph due north).
Acceleration happens when:
* The speed changes: If you're driving and press the gas pedal, your speed increases, and you're accelerating. If you brake, your speed decreases, and you're also accelerating (in the opposite direction).
* The direction changes: Even if your speed stays constant, if your direction changes, you're accelerating. Think of a car going around a circular track at a constant speed. It's constantly changing direction, so it's constantly accelerating.
Examples of an object staying at the same speed but still accelerating:
* Circular motion: An object moving in a circle at a constant speed is constantly accelerating because its direction is changing.
* Satellite in orbit: A satellite orbiting Earth maintains a relatively constant speed but is constantly accelerating towards Earth due to gravity.
Key Takeaway:
Acceleration is about change in velocity. It's possible for an object to have constant speed and still be accelerating if its direction is changing.
