When a boy weighing 20 kg 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 another boy weighing 40 kg?
When a boy weighing 20 kg 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 another boy weighing 40 kg?
The correct option is A By sitting at a distance of 1 m from the centre on the side opposite to the first boy.
Weights of the two boys : W1 = 20 kg, W2 = 40 kg
Length of see-saw = 4 m
Distance from the centre = 2 m
Moment of Force = Force × perpendicular distance
Then, the principle of moments can be written as follows:
Moment in clockwise direction = Moment in anticlockwise direction
W1 × d1 = W2 × d2
20 × 2 = 40 × d2
d2 = 20×240 = 1 m
Thus, the other boy can sit at a distance of 1m from the centre on the side opposite to the first boy, so that the long see - saw can be brought to the horizontal position.
By sitting at a distance of 1 m from the centre on the side opposite to the first boy.
Weights of the two boys : W1 = 20 kg, W2 = 40 kg
Length of see-saw = 4 m
Distance from the centre = 2 m
Moment of Force = Force × perpendicular distance
Then, the principle of moments can be written as follows:
Moment in clockwise direction = Moment in anticlockwise direction
W1 × d1 = W2 × d2
20 × 2 = 40 × d2
d2 = 20×240 = 1 m
Thus, the other boy can sit at a distance of 1m from the centre on the side opposite to the first boy, so that the long see - saw can be brought to the horizontal position.
