Question

the volume of metal in a metallic cylindrical pipe is 748cm³ its length is 14 cm and it's external radius is 9cm find its thickness

Answer 1

Hope u like my process
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=> Let the inner radius be r cm

=> External Radius = R = 9 cm

=> Height of pipe = h= 14 cm

=> Volume of metallic cylinder

$= \pi {r}^{2} h = 748 \: cm {}^{3} \\ \\ where \: \: \pi = \frac{22}{7} \\ \\ \underline{ \: \: \: \: \: so \: \: \: \: \: \: }\\ \\ = > \it \green{\frac{22}{7} \times {r}^{2} \times 14 }= \green{748} \\ \\ = > \it \green{ {r}^{2} } = \green{ \frac{748}{44} } = \green{ \frac{68}{4} } = \green{17} \\ \\ = > \boxed{ \bf \: r = \green{ \sqrt{17} } = \underline{ \orange{4.12 \: \: cm}}}$

Now the thickness can be determined by

=> R - r = 9 - 4.12 = 4.88 cm

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