1. In physics, is acceleration supposed to be positive or negative?
Answer:
Acceleration can be either positive or negative, depending on the direction of the acceleration relative to the chosen coordinate system.
- Positive acceleration means the object is increasing its velocity in the positive direction.
- Negative acceleration means the object is increasing its velocity in the negative direction, or slowing down if it was going in the positive direction.
So it’s not about “good or bad” — it’s about direction.
2. In physics, is deceleration supposed to be positive or negative?
Answer:
Deceleration usually refers to when an object is slowing down.
In physics, this often shows up as negative acceleration, but it depends on the direction of motion:
- If the object is moving in the positive direction and slows down, acceleration is negative.
- If it’s moving in the negative direction and slows down, acceleration is positive.
So, deceleration = acceleration in the opposite direction to motion, which typically appears as a negative value in common problems.
3. What is the difference between acceleration and deceleration?
Answer:
|
Acceleration |
Deceleration |
|
Change in velocity (can be positive or negative) |
A special case of acceleration where the object slows down |
|
Can increase or decrease speed |
Always decreases speed |
|
Depends on direction and motion |
Always acts opposite to the direction of |