- #1
Nnk
- 5
- 0
Homework Statement
A child of mass m is supported on a light plank by his parents, who exert the forces F1 and F2 as indicated.
Find the forces required to keep the plank in static equilibrium. Use the right end of the planks as the axis of rotation. ( Answer: F1=(1/4)mg, F2=(3/4)mg )
Suppose the child moves to a new position, with the result that the force exerted by the father is reduced to 0.60mg. How far did the child move?
Homework Equations
Torque = F*r
Net force acting on plant equal to zero: F1+F2-mg=0
Net torque acting on plant equal to zero: -F1(L) + mg(L/4) = 0
The Attempt at a Solution
I have no Idea how to find the distance, as when I tried it, the "L" cancels out...