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# Moment Watch

1. Define the moment of a couple? (2)
Can i have a proper definition , every mark scheme is different?
2. (Original post by Ayaz789)
Define the moment of a couple? (2)
Can i have a proper definition , every mark scheme is different?
The moment of a couple is the product of either of the forces of magnitude of the couple and the perpendicular distance between those forces.

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

3. (Original post by Smithenator5000)
The moment of a couple is the product of either of the forces of magnitude of the couple and the perpendicular distance between those forces.

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

If i wrote Moment is the force * the perpendicular distance , would i get 2 marks?
4. (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.'
5. (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?
6. (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?
7. (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
8. (Original post by Ayaz789)
Im on my phone rn so ill send it tonight
Okay, then.
9. I would define a moment as:

Force * perpendicular distance (to the line of action of the force), from a pivot point.
10. (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
11. (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.
12. (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.
13. the moment when a couple breaks up
yaay he's available
14. (Original post by iqra2159)
the moment when a couple breaks up
yaay he's available
lol wth
15. (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"
16. (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.
17. (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.
18. (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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