Accelration Help: Questions Answered

[NIZBIT]

Just a couple of questions I'm banging my head on. Any help would be great!

1. Does your accelration have to be negative when you are slowing down?

If I started in a negative direction back towards my initial frame of reference,
acceleration would be positive? But isn't that still speeding up?

2. It is a velocity time graph. I'll explain the best I can. It wants to know which is accelrating faster. It is showing 2 graphs. Graph A is a positive velocity with a positive acceleration and it has a small slope so all of this is slowly happening. Graph B is positive velocity with a negative accelration and the slope is larger so it is quickly happening.

So when they ask this does it matter if its acclerating or deaccelerating?

 

[Kurdt]

1. Think of acceleration as a vector. Does a vector have to be negative?

2. Acceleration is the rate of change of speed with respect to time so when it asks which is accelerating faster do you think it should matter if it is accelerating or decellerating?

 

[NIZBIT]

So I could have a negative velocity with a positive accelration hence slowing down?

 

[Kurdt]

I think you've hit the nail on the head.