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# Velocity & Time Graphs, HELP!!!!!! watch

1. I'm rather confused about the idea that the area under a velocity time graph represents the distance, shouldn't it represent the displacement, as displacement is a quantity derived from velocity (vector quantity). And if it does represent displacement how exactly can the displacement of an upward projectile equal zero (assuming that air resistance is negligible and that the projectile falls back down to the point of projection)? I do understand that if a projectile travels 5m up and that 5m down the displacement equals 0m and the distance equals 10m, though i can't seem to establish this from a velocity time graph (not the absolute value of velocity).
2. (Original post by Paranoid_Glitch)
I'm rather confused about the idea that the area under a velocity time graph represents the distance, shouldn't it represent the displacement, as displacement is a quantity derived from velocity (vector quantity). And if it does represent displacement how exactly can the displacement of an upward projectile equal zero (assuming that air resistance is negligible and that the projectile falls back down to the point of projection)? I do understand that if a projectile travels 5m up and that 5m down the displacement equals 0m and the distance equals 10m, though i can't seem to establish this from a velocity time graph (not the absolute value of velocity).
(Original post by EricPiphany)
^^ this is pretty much what you're looking for, if you want an analogy imagine the first section of that graph is a car reversing for 5m for example. Then the car moves forward 5m metres thus 0m displacement.
3. (Original post by thefatone)
^^ this is pretty much what you're looking for, if you want an analogy imagine the first section of that graph is a car reversing for 5m for example. Then the car moves forward 5m metres thus 0m displacement.
Thanks though what i'm not sure about is whether the area represents distance or displacement, & why does it represent that?
4. (Original post by Paranoid_Glitch)
Thanks though what i'm not sure about is whether the area represents distance or displacement, & why does it represent that?
5. (Original post by Paranoid_Glitch)
Thanks though what i'm not sure about is whether the area represents distance or displacement, & why does it represent that?
depends if the graph is speed-time or velocity-time

Speed-time graph- area under graph is distance
Velocity-time graph- area under graph is displacement
6. (Original post by thefatone)
depends if the graph is speed-time or velocity-time

Speed-time graph- area under graph is distance
Velocity-time graph- area under graph is displacement
So the resultant displacement would be the sum of the two displacements of each area? Though if i took the absolute value it would equal the distance?
7. Thank's already watched it, but he took the absolute value of velocity so is that why it represents distance? The title of the video seems rather misleading.
8. (Original post by Paranoid_Glitch)
So the resultant displacement would be the sum of the two displacements of each area? Though if i took the absolute value it would equal the distance?
yes that's right the sum of both displacements will give you the resultant displacement

absolute value
noun
1.MATHEMATICS
the magnitude of a real number without regard to its sign.

displacement gives direction so negative and positive direction makes a difference.
direction is what makes displacement displacement, otherwise it'd be distance.
remember that displacement is a vector.

in other words
distance= how far something has gone
displacement= how far something has gone taking into account its direction
9. (Original post by thefatone)
yes that's right the sum of both displacements will give you the resultant displacement

absolute value
noun
1.MATHEMATICS
the magnitude of a real number without regard to its sign.

displacement gives direction so negative and positive direction makes a difference.
direction is what makes displacement displacement, otherwise it'd be distance.
remember that displacement is a vector.

in other words
distance= how far something has gone
displacement= how far something has gone taking into account its direction
Thanks i finally got it.
10. (Original post by Paranoid_Glitch)
Thanks i finally got it.
sounds good

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