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can max acceleration be negtaive (1 Viewer)

..:''ooo

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can max acceleration be negative
like -20 and 20 are acclerations but just differnt in direction

so which one can be said to be maximum?
 

Slidey

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Acceleration is a vector; it has direction. In the case of a particle moving in a straight line, it has two directions: forward and backwards, or positive and negative.

When you have -20 acceleration, you are deccelerating. When you have 20 you are increasing in velocity.

20 > -20, so 20 is the maximum.

Maximum refers to the magnitude as well as the direction in this case, not just the magnitude.
 

acmilan

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I was always under the impression that both 20 and -20 could be considered maximum. An acceleration of -20 could just be thought of as an acceleration of magnitude 20 in the opposite direction of the conventional positive direction, whilst an acceleration of 20 could just be thought of as an acceleration of magnitude 20 in the direction of the conventional positive direction
 

Slidey

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Hmm. I guess it'd be a good idea to just mention that both have maximum magnitude, then?
 

Will Hunting

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Take the absolute value of the accelerations as the maximum, since maximum is asking for the magnitude of the change in velocity, direction notwithstanding.
 

..:''ooo

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i just read those hsc solution
and it says

max acceleration = | a |

so you should just state the magnitude
 

withoutaface

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Common sense situation:

We have one car accelerating at 20m.s<sup>-2</sup> and another at 30m.s<sup>-2</sup> in the other direction, but we define the direction of the first car to be positive, what we define to be positive doesn't mean the acceleration of the second car isn't greater.
 

Ghost1788

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it says acceleration refering to the positive component of the vector not the negative component which is associated with deceleration... therefore the maximum is 20
 

|Axis_

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For those of u saying that the maximum is "20 in the positive direction", r u guys saying that

for vectors
u = (u1, u2, ..., un)
v = (v1, v2, ..., vn)

max{u , v} is defined?

What does it mean for one vector to be "greater" than another!?!

I'd say the question's referring to magnitude.
 

gordo

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Slide Rule said:
Acceleration is a vector; it has direction. In the case of a particle moving in a straight line, it has two directions: forward and backwards, or positive and negative.

When you have -20 acceleration, you are deccelerating. When you have 20 you are increasing in velocity.

20 > -20, so 20 is the maximum.

Maximum refers to the magnitude as well as the direction in this case, not just the magnitude.
if u are going at -20 once u hit the left side of 0 on the number plane u begin accelerating again
 

withoutaface

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Ghost1788 said:
it says acceleration refering to the positive component of the vector not the negative component which is associated with deceleration... therefore the maximum is 20
Deceleration is such an annoying term for something which is essentially the same thing.
 

gordo

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yeh,
y not call it develocity wen u are going in the opposite direction
or antidistance
 

Slidey

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gordo said:
if u are going at -20 once u hit the left side of 0 on the number plane u begin accelerating again
If you'd have read my post you would have realised I wasn't disputing that.

And anti-distance is wouldn't work. Distance is a scalar.
 

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