A balanced lever has two weights on it, the first with mass 16 kg 16kg and the second with mass 21 kg21kg. If the first weight is 3 m3m from the fulcrum, how far is the second weight from the fulcrum?

1 Answer
Jan 21, 2016

Use the guide below. Plug in given values and calculate.

Explanation:

A body which has no tendency to rotate under the combined result of a number of forces acting on it is called to be in a balanced state.

The rotational tendency of a force is called Moment of the force.

Moment ==Force times ×Distance=F times D=F×D

where DD is the length of Moment arm, which is perpendicular distance between the line of action of the force and the center of moments.

Also in a balanced lever clockwise moments are equal to clockwise moments.

In the given question, forces acting are two weights for which
F=m.gF=m.g where gg is acceleration due to gravity.

If dd is the length of Moment arm, i.e ., perpendicular distance between the weight and the fulcrum, then moment of one force about the fulcrum is equal and opposite to the moment of other force about the fulcrum.

Stating mathematically
Moment_1=Moment_2Moment1=Moment2

or m_1.g.d_1=m_2.g.d_2m1.g.d1=m2.g.d2
implies m_1.d_1=m_2.d_2m1.d1=m2.d2