Question

Marcel is helping his two children, Jacquesand Gilles, to balance on a seesaw so that they will be able tomake it tilt back and forth without the heavier child, Jacques,simply sinking to the ground. Given that Jacques, whose weight is, is sitting at distance to the left of the pivot, at what distance $L_1$ should Marcel place Gilles, whose weight is , to the right of the pivot to balance the seesaw?

Express your answer in terms of, , and .

$MFS_to_0_v1_a.jpg$

Answer 1

The torques must be equal in magnitude, and torque is forcetimes distance from the point of rotation so

   W L = w L₁

And    L₁ = L (W/w)     so the smaller guy is further from thecenter, proportional to his weight.