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Size:  130.6 KB hi, for part b) of this question I got it wrong and would like some help pls. I have checked the mark scheme and realised that the position of D is actually closer to b then a. How do you know where d would be as whenever I am asked to find distance like this I always assume the pivot is very close to a... Thanks.Attachment 517721517725
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    (Original post by coconut64)
    hi, for part b) of this question I got it wrong and would like some help pls.
    How does it matter? Place it anywhere you like and call the distance x - the algebra will sort itself out. You don't need to know whether d will be closer to whatever.

    You should take moments from A or B instead of the centre.
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    (Original post by Zacken)
    How does it matter? Place it anywhere you like and call the distance x - the algebra will sort itself out. You don't need to know whether d will be closer to whatever.

    You should take moments from A or B instead of the centre.
    Got the right answer now thanks. I realised I used 6.5g not 6.5N .
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    (Original post by coconut64)
    Name:  Screenshot_2016-04-01-13-26-45.png
Views: 77
Size:  130.6 KB hi, for part b) of this question I got it wrong and would like some help pls. I have checked the mark scheme and realised that the position of D is actually closer to b then a. How do you know where d would be as whenever I am asked to find distance like this I always assume the pivot is very close to a... Thanks.Attachment 517721517725
    You should have taken moments about A or B instead.

    Then you don't have to worry if the moment from the reaction of the pivot will be clockwise or anticlockwise. The algebra should work itself out anyway as Zacken has said.

    You should have noticed a problem when you assumed x was less than 50 but your answer was more than 50.
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    (Original post by coconut64)
    Got the right answer now thanks. I realised I used 6.5g not 6.5N .
    No problem!
 
 
 
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