Question

radius of a solid copper cylinder us 4.2 cm and height is 16 cm how many disc of radius 0.7cm and height 0.2 cm can be made from melting the cylinder ​

Answer 1

$\huge \mathfrak{answer}$

number of disc = 480

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✥Question✥

radius of a solid copper cylinder us 4.2 cm and height is 16 cm how many disc of radius 0.7cm and height 0.2 cm can be made from melting the cylinder

step to step explanation:

$\sf{radius \: of \: solid \: copper}$

$\sf{R = 4.2}$

$\sf{height \: of \: solid \: copper \: h \: = 16cm}$

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volume of solid copper cylinder = πR²H

so according to problem (formula)

$\rm \red{ = \frac{22}{7} \times 4.2 \times 16}$

$\sf \red{ = 22 \times 0.6 \times 16}$

$\sf \red{ = 22 \times 9.6}$

$\sf \red{ = 211.2 {cm}^{2}}$

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$\rm{thickness \: of \: disc \: h \: = 0.2}$

$\rm{radius \: of \: disc \: r = \frac{diamter}{2}}$

$\rm{ \frac{1.4}{2} = 0.7}$

$\bf{ { \boxed{ \red{ \tt{volume \: of \: disc = \pi {r}^{2}h \: }}}}}$

$\tt{ = \frac{22}{7} \times 0.7 \times 0.2}$

$\tt{ = 22 \times 0.1 \times 0.2}$

$\tt{ = 0.44 {cm}^{2}}$

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$\bf{ \boxed{ \green{ \tt{no.of \: disc = \frac{volume \: of \: cylnd \: cppr \: solid}{volume \: of \: each \: disc \: }}}}}$

$\rm \red{ \frac{211.2}{0.44} = 480}$

Number of disc = 480