Question

How much iron is needed to make a rod of length 60 cm and diameter 1 .4 cm
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Answer 1

Given that length of rod should be 60cm long and diameter 1.4cm.

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To Find iron needed to make given rod.

$\begin{gathered} \\ \qquad {\rule{200pt}{2pt}} \end{gathered}$

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${\Large{\maltese \: {\underline{\underline{\gray{\sf{Solution}}}}}}}$

Formula Using

• $\boxed{\begin{array}{ccc} \sf Radius=\dfrac{Diameter}{2} \\ \\ \sf Volume_{\:Cylinder}=\pi r^2 l \end{array}}$

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${\large{\bigstar \: {\underline{\sf{Calculation\: :-}}}}}$

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Calculating Radius

$\begin{gathered} \\ \qquad {\rule{200pt}{2pt}} \end{gathered}$

${\dashrightarrow{\sf{\quad Radius=\dfrac{diameter}{2}}}}$

Putting Values...

${\dashrightarrow{\sf{\quad Radius=\dfrac{1.4}{2}}}}$

${\dashrightarrow{\sf{\quad Radius=\cancel\dfrac{1.4}{2}=0.7}}}$

${\rightsquigarrow{\quad{\underline{\boxed{\sf{ Radius=0.7cm}}}}}}$

$\begin{gathered} \\ {\rule{150pt}{2pt}} \end{gathered}$

Calculating Volume

${\dashrightarrow{\sf{\quad Volume_{\:Cylinder}=\pi r^2 l}}}$

Putting Values...

${\dashrightarrow{\sf{\quad Volume=\dfrac{22}{7} \times 0.7 \times 0.7 \times 60}}}$

${\dashrightarrow{\sf{\quad Volume=\dfrac{22}{\bcancel{7}} \times \bcancel{0.7} \times 0.7 \times 60}}}$

${\dashrightarrow{\sf{\quad Volume=22 \times 0.7 \times 0.1 \times 60}}}$

${\dashrightarrow{\sf{\quad Volume=924}}}$

${\rightsquigarrow{\quad{\underline{\boxed{\sf{Volume=924cm^3}}}\pink\bigstar}}}$

$\begin{gathered} \\ \qquad {\rule{200pt}{2pt}} \end{gathered}$

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${\therefore}$Iron needed to make given rod is $\bf{924cm^3}$

$\begin{gathered} \\ {\underline{\gray{\rule{200pt}{5pt}}}} \end{gathered}$