Question

When a boy weighing 20 kgf sits at one end of a 4 m long see-saw, it gets depressed at this end. It can be brought to the horizontal position if a man weighing 40 kgf sits at ______.

Options

• the opposite end of the see-saw

• one-metre distance on the side of the boy

• one-metre distance on the side opposite to the boy

• the middle of the sea-saw

Answer 1

When a boy weighing 20 kgf sits at one end of a 4 m long see-saw, it gets depressed at this end. It can be brought to the horizontal position if a man weighing 40 kgf sits at one-metre distance on the side opposite to the boy.

Explanation:

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.