Why do people state velocity without the direction???

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#1
It is always told that speed is a scalar and velocity is vector, as in it has a direction as well. But whenever you come across questions, they always state that something is a velocity but DO NOT give the direction! e.g. they will just say that the velocity is 5m/s not 5m/s and direction! It annoys me so much!
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4 years ago
#2
Velocity without direction is a contradiction in terms.
1
4 years ago
#3
Although I agree that it's 'incorrect', I believe that a velocity with no direction given is usually assumed to be going in the forwards direction.
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4 years ago
#4
But yeah, I remember memorising the definition: "velocity is speed in a given direction".
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4 years ago
#5
You'd be correct given they don't specify the magnitude of thevelocity (which is the same as speed - a scalar quantity). The same goes for force - a vector quantity. Chances are if asked to calculate something relating to force they (should) specifically ask for the magnitude of the force
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#6
(Original post by surina16)
Although I agree that it's 'incorrect', I believe that a velocity with no direction given is usually assumed to be going in the forwards direction.
Oh, well i guess that makes a bit more sense
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4 years ago
#7
(Original post by Retropattern)
It is always told that speed is a scalar and velocity is vector, as in it has a direction as well. But whenever you come across questions, they always state that something is a velocity but DO NOT give the direction! e.g. they will just say that the velocity is 5m/s not 5m/s and direction! It annoys me so much!
(Original post by surina16)
Although I agree that it's 'incorrect', I believe that a velocity with no direction given is usually assumed to be going in the forwards direction.
It's not incorrect. Given that you're doing the basic mechanics modules, all you've learn is motion in two dimensions. This comes with direction. A velocity of 5 m/s has the direction given by a +, this indicates movement towards the right or towards the top (by default, otherwise it's in whatever direction you're taking to be the positive orientation) since you only work in two dimensions. A velocity of -5 m/s means that movements is towards the left or the bottom.

Because you only do simple models in two dimensions, the direction of velocity is notated by + or -. When you get to higher mechanics modules and deal with three dimensional models or circular motions then directions will be given vectorially or radially.
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4 years ago
#8
(Original post by Zacken)
It's not incorrect. Given that you're doing the basic mechanics modules, all you've learn is motion in two dimensions. This comes with direction. A velocity of 5 m/s has the direction given by a +, this indicates movement towards the right or towards the top (by default, otherwise it's in whatever direction you're taking to be the positive orientation) since you only work in two dimensions. A velocity of -5 m/s means that movements is towards the left or the bottom.

Because you only do simple models in two dimensions, the direction of velocity is notated by + or -. When you get to higher mechanics modules and deal with three dimensional models or circular motions then directions will be given vectorially or radially.
Thanks for the explanation . As you said, I've only seen it as + or - and didn't even think of anything outside of this
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