A balanced lever has two weights on it, the first with mass #7 kg # and the second with mass #25 kg#. If the first weight is # 6 m# from the fulcrum, how far is the second weight from the fulcrum?

1 Answer
Dec 24, 2015

Answer:

#1,68m#

Explanation:

We may use the second condition for static equilibrium to solve this problem, that is, that the resultant torque of the system must be zero.
ie, #sum vectau=0#, where #vectau = vecr xx vecF# is the vector cross product of the position vector from the axis of rotation (fulcrum) to the applied force and the applied force.

So in this case,

#r_1F_1-r_2F_2=0#

#therefore (6xx7g)-(r_2xx25g)=0#

#therefore r_2=(6xx7xx9,8)/(25xx9,8)=1,68m#.