If velocity decreases continuously, acceleration is negative acceleration.
Based on the provided reference, a clear conclusion can be drawn about the nature of acceleration when velocity continuously decreases.
Understanding Acceleration and Velocity
Acceleration is the rate at which velocity changes over time. Velocity is a vector quantity, meaning it has both magnitude (speed) and direction. Changes in either speed or direction (or both) constitute acceleration.
The reference specifically addresses changes in the magnitude of velocity (speed) in a continuous manner:
From the above points, we can conclude that if velocity continuously increases, then the acceleration is called positive acceleration and when velocity continuously decreases, then the acceleration is defined as negative acceleration. When velocity is constant, then the acceleration is called zero acceleration.
This statement provides the definition of acceleration in three key scenarios:
- Velocity increases continuously: Positive acceleration.
- Velocity decreases continuously: Negative acceleration.
- Velocity is constant: Zero acceleration.
Therefore, directly from the provided information, we can conclude that if velocity decreases continuously, the acceleration is defined as negative acceleration.
What is Negative Acceleration?
Negative acceleration, as defined here, often indicates that the acceleration is acting in the opposite direction to the velocity. This causes the object to slow down. It's important to note that "negative" here refers to the direction relative to a chosen positive direction, or specifically, the effect on the velocity magnitude when velocity and acceleration are in opposing directions.
Key Takeaway:
| Velocity Change | Conclusion about Acceleration (based on reference) | Effect |
|---|---|---|
| Continuously Increases | Positive Acceleration | Speeding up |
| Continuously Decreases | Negative Acceleration | Slowing down |
| Remains Constant | Zero Acceleration | Maintaining constant speed and direction |
Practical Insights and Examples
- Applying Brakes: When a car is moving forward and the driver applies the brakes, the velocity is in the forward direction, but the acceleration (or deceleration) is in the backward direction. This causes the forward velocity to decrease continuously. This is an example of negative acceleration.
- Ball Thrown Upwards: As a ball travels upwards after being thrown, its upward velocity continuously decreases until it reaches the peak. The acceleration due to gravity is always acting downwards. While the velocity is upwards, the downward acceleration is "negative acceleration" relative to the upward velocity, causing the ball to slow down.
In summary, based on the definition provided in the reference, a continuous decrease in velocity is the defining characteristic of negative acceleration.
