Question

A see saw 8 m long is balance in the middle. Two children of mass 30 kgf and 40 kgf are sitting on the same side of fulcrum respectively. Where must a lady weighing 60 kgf sit from the fulcrum, so as to balance the children

Answer 1

Hi.

Good Question and Keep Progressing.

Here is your answer---

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  Length of the See saw =  8 m.

    According to the Principle of moments,In an equilibrium,

             Anti-Clockwise Moments = Clockwise Moments

According to the Question, Two children are sitting on the Same side of the see-saw, which is Balanced in the middle.

Thus,

For 30 kgf mass(m1)

Distance From the middle of the see saw(d1) = 1.5 m


For 40 kgf mass(m2)

Distance From the middle of the see-saw(d2) = 3.5 m


For 60 kgf(m) mass,

Distance at which the child weighing 60 kgf would sit on other side of the see- saw = d m

From the principle of Moments,
    Clockwise Moments = Anti - Clockwise moments
       m1 × d1 + m2 × d2 = m × d
       30 × 1.5 + 40 × 3.5 = 60 × d
                     45 + 140   = 60 × d
                              185  = 60 × d
                                   d = 185/60
                                   d = 3.08 m

Thus, the distance at which the child weighing 60 kgf would sit is 3.08 m on other side of the see-saw.

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Hope it Helps.

Have a nice day.

Answer 2

Answer:

3.08

Explanation:

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