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Question
When a boy weighing 20 kgf sits at one end of a 4 m long see-saw, it gets depressed at this end. How can it be brought to the horizontal position by a man weighing 40 kgf.
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Solution
Weight of boy (W1) = 20 kgf
W2 = 40 kgf
Length of see-saw = 4m
distance from centre = 2m
W1 × d1 = W2 × d
20 × 2 = 40 × d
d = `(20 xx 2)/40`
= 1 m
By sitting at a distance of 1 m from two centre on the side opposite to the boy.
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