You are Here: Home >< A-levels

# What is acceleration?

Announcements Posted on
Last day to win £100 of Amazon vouchers - don't miss out! Take our quick survey to enter 24-10-2016
1. What does the term 'negative acceleration' mean?
is it deceleration in the positive direction or is it acceleration in the negative direction?
2. Acceleration in the negative direction.
Negative acceleration and Deceleration are the same thing
EDIT: I'm sorry, i was thinking of something else.
Deceleration is a reduce in speed/time
Negative acceleration is Acceleration in the opposite direction.
Acceleration in the negative direction.
Negative acceleration and Deceleration are the same thing
But say if car is travelling and then it slows down and eventually stops, it is decelerating but how it is accelerating in the negative direction at the same time?
4. Positive acceleration:

----------------->>

Negative acceleration:

<<-----------------

They're considered positive and negative as they're usually measured along the x-axis - so x increasing (+ve, to the right) or decreasing (-ve, left). In future you may learn about vector direction but I wouldn't worry about that now.

Deceleration is just a term that describes a decrease in speed. So it can be positive or negative acceleration, depending on the direction of motion of the object.
5. (Original post by IDontKnowReally)
But say if car is travelling and then it slows down and eventually stops, it is decelerating but how it is accelerating in the negative direction at the same time?
Deceleration is a type of acceleration.

It just describes acceleration in the direction opposite to motion - hence the object slows down.
6. (Original post by IDontKnowReally)
But say if car is travelling and then it slows down and eventually stops, it is decelerating but how it is accelerating in the negative direction at the same time?
I would just use negative acceleration. Acceleration is the change in velocity over time so if you are slowing down then you are negatively accelerating.
7. (Original post by Alexion)
Deceleration is a type of acceleration.

It just describes acceleration in the direction opposite to motion - hence the object slows down.
So if there is acceleration in one directon, it doesnt necessarily mean the object willl move in that direction?
Would an object have negative acceleration if the accerelation on it was opposite to the direction of motion?
8. (Original post by IDontKnowReally)
So if there is acceleration in one directon, it doesnt necessarily mean the object willl move in that direction?
Would an object have negative acceleration if the accerelation on it was opposite to the direction of motion?
It really depends on the speed of the particle.

Imagine a particle moving forward at 10ms-1, with an acceleration of -2ms-2 - this means that the acceleration is acting in the opposite direction to motion. Negative acceleration, if you will.

The particle will decelerate to 0ms-1 over the course of 5 seconds. But, if it still has the same acceleration, it will begin to speed up in the direction of the acceleration - the opposite direction to the way it was moving before.
9. (Original post by Alexion)
It really depends on the speed of the particle.

Imagine a particle moving forward at 10ms-1, with an acceleration of -2ms-2 - this means that the acceleration is acting in the opposite direction to motion. Negative acceleration, if you will.

The particle will decelerate to 0ms-1 over the course of 5 seconds. But, if it still has the same acceleration, it will begin to speed up in the direction of the acceleration - the opposite direction to the way it was moving before.
That makes a lot of sense. Thank you!
10. (Original post by IDontKnowReally)
That makes a lot of sense. Thank you!
11. (Original post by IDontKnowReally)
What does the term 'negative acceleration' mean?
is it deceleration in the positive direction or is it acceleration in the negative direction?
Simple definition :
Acceleration is the rate at which velocity changes over time

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: May 22, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Today on TSR

### How does exam reform affect you?

From GCSE to A level, it's all changing

Poll

## All the essentials

### Student life: what to expect

What it's really like going to uni

### Essay expert

Learn to write like a pro with our ultimate essay guide.

### Create a study plan

Get your head around what you need to do and when with the study planner tool.

### Resources by subject

Everything from mind maps to class notes.

### Study tips from A* students

Students who got top grades in their A-levels share their secrets