Question

Calculate the force required to lift a load of 60 N, placed at a distance of 3 m, from the fulcrum. The effort force is applied at a distance of 6 cm from the fulcrum.

Answer 1

$F_1=60N,l_1=3m,l_2=6cm,F_2=?$
Left hand side moment, about fulcrum
$=60\times 3=180Nm.$
Right hand side movement, about fulcrum $=6\times {10}^{-2}\times xNm.$
According to principle of moment,
$L.H.M=R.H.M$
$180=6\times {10}^{-2}\times x$
$x=\frac{180}{6\times {10}^{-2}}=3000N$
Therefore, a force of 3000 N is required to lift the load.