Question

A system of pulleys is used to lift a load of $1000kgwt$. If the efficiency of the pulley system is $80\%$ and velocity ratio is $20$, find the effort required to lift the load.

Answer 1

Step 1: Given data

$$\begin{gathered} Load,L=1000kgwt \\ Efficiency=80\% \\ Velocityratio(V.R)=20 \end{gathered}$$

Step 2: Finding the effort required to lift the load

We know that, $Efficiency=\frac{Mechanicaladvantage(M.A)}{Velocityraio(V.R)}$

$$\begin{gathered} 80=\frac{M.A}{20}\times 100 \\ M.A=\frac{80}{5}=16 \\ M.A=\frac{load}{effort} \\ effort=\frac{load}{M.A} \\ effort=\frac{1000}{16} \\ effort=62.5kgwt \end{gathered}$$

Thus, the effort required to lift the load is $62.5kgwt$.