Lychee628
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Define the moment of a couple? (2)
Can i have a proper definition , every mark scheme is different?
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Smithenator5000
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(Original post by Ayaz789)
Define the moment of a couple? (2)
Can i have a proper definition , every mark scheme is different?
The moment  M of a couple is the product of either of the forces of magnitude  F of the couple and the perpendicular distance  d between those forces.
Name:  couple.PNG
Views: 216
Size:  2.5 KB





M = Fd

For example, if two forces of magnitude  6 N acted on a body and the perpendicular distance between them was  10 m , the moment  M would be:





M = (6)(10) = 60 Nm
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Lychee628
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(Original post by Smithenator5000)
The moment  M of a couple is the product of either of the forces of magnitude  F of the couple and the perpendicular distance  d between those forces.
Name:  couple.PNG
Views: 216
Size:  2.5 KB





M = Fd

For example, if two forces of magnitude  6 N acted on a body and the perpendicular distance between them was  10 m , the moment  M would be:





M = (6)(10) = 60 Nm
If i wrote Moment is the force * the perpendicular distance , would i get 2 marks?
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Smithenator5000
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(Original post by Ayaz789)
If i wrote Moment is the force * the perpendicular distance , would i get 2 marks?
I'm no examiner but I think that what you just typed would earn one mark. The question asks specifically for the moment of a couple, so you should specify which force and which distance should be used in the calculation. Of course for two marks, do not include the diagram and example. I would probably write the following:

'(The moment of a couple is) the product of the magnitude of one the forces in a couple and the perpendicular distance between those two forces.'
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Lychee628
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(Original post by Smithenator5000)
I'm no examiner but I think that what you just typed would earn one mark. The question asks specifically for the moment of a couple, so you should specify which force and which distance should be used in the calculation. Of course for two marks, do not include the diagram and example. I would probably write the following:

'(The moment of a couple is) the product of the magnitude of one the forces in a couple and the perpendicular distance between those two forces.'
But in the ms it says the force * perpendicular distance at a given point?
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Smithenator5000
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(Original post by Ayaz789)
But in the ms it says the force * perpendicular distance at a given point?
Could you please supply a link to it so I can read it?
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Lychee628
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(Original post by Smithenator5000)
Could you please supply a link to it so I can read it?
Im on my phone rn so ill send it tonight
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Smithenator5000
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(Original post by Ayaz789)
Im on my phone rn so ill send it tonight
Okay, then.
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Wunderbarr
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I would define a moment as:

Force * perpendicular distance (to the line of action of the force), from a pivot point.
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Lychee628
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(Original post by Wunderbarr)
I would define a moment as:

Force * perpendicular distance (to the line of action of the force), from a pivot point.
That would get me 2 marks yeah
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Wunderbarr
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(Original post by Ayaz789)
That would get me 2 marks yeah
Just remember, moments exist because there are forces that cause rotation around a pivot point, at a distance from the pivot point.

So the part about a "at a given point" is pretty much essential.

Lastly, the perpendicular distance is the shortest distance to the line of action of the force.
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Lychee628
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(Original post by Wunderbarr)
Just remember, moments exist because there are forces that cause rotation around a pivot point, at a distance from the pivot point.

So the part about a "at a given point" is pretty much essential.

Lastly, the perpendicular distance is the shortest distance to the line of action of the force.
Okay thanks.
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.Iqra.
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the moment when a couple breaks up
yaay he's available
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soIiIoquy
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(Original post by iqra2159)
the moment when a couple breaks up
yaay he's available
lol wth
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voltz
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(Original post by Ayaz789)
Define the moment of a couple? (2)
Can i have a proper definition , every mark scheme is different?
"Force multiplied by the perpendicular distancce from the pivot"
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M0nkey Thunder
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(Original post by voltz)
"Force multiplied by the perpendicular distancce from the pivot"
Consider the fact that he said "of a couple". There are 2 forces in action here, both with equal magnitude and opposite direction as one of the first posters said.

What you defined was a moment. The moment of a couple would be:

The magnitude of one of the forces within a couple multiplied by the perpendicular distance between the two forces.
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voltz
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(Original post by M0nkey Thunder)
Consider the fact that he said "of a couple". There are 2 forces in action here, both with equal magnitude and opposite direction as one of the first posters said.

What you defined was a moment. The moment of a couple would be:

The magnitude of one of the forces within a couple multiplied by the perpendicular distance between the two forces.
That would not be the moment, it would be the torque you are calculating.

Moment: Force multiplied by pependicular distance from the pivot

Torque: One force in a couple force multiplied by the perpendicular distance between the two forces.
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M0nkey Thunder
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(Original post by voltz)
That would not be the moment, it would be the torque you are calculating.

Moment: Force multiplied by pependicular distance from the pivot

Torque: One force in a couple force multiplied by the perpendicular distance between the two forces.
But the problem is, the OP is calculating the moment of a couple. There is no reference to a pivot and so you must assume that they mean a torque.
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