Question

A block and tackle system consists of 4 pulleys is used to lift a load of 150N by applying a force of 60N. What should be the value of reh efficiency of this pulley system?

Answer 1

★Given:-

$\bullet \textbf{Load = 150N}$

$\bullet \: \textbf{Effort = 60N}$

$\bullet \textbf{No. of pulley n = 4 }$

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★To Find:-

$\bullet \textbf{The efficiency of the given Pulley system}$

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★Solution:-

$\textbf{As \: we \: know \: that,}$

η

$\textbf{η = M.A /V.R}$

$\textbf{Where,</p><p></p><p>}$

$\textbf{η \: is \: efficiency}$

$\textbf{M.A \: is \: Mechanical \: Advantage}$

$\textbf{V.A \: is \: Velocity \: Ratio}$

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$\textbf{M.A} = \frac{Load}{Effort} = \frac{150}{60} = 2.5$

$\textbf{V.R = No. \: of \: pulleys \: used \: = 4}$

$\textbf{η = } \frac{2.5}{4} \times 100 \%$

$= 62.5\%$

$\therefore \textbf{Eficiency = 62.5\%}$