Question

A slab of iron of dimensions 60 cm x 20 cm x 28.26 cm is used to cast an iron pipe. the outer diameter of the pipe is 10 cm and the thickness is 1 cm, calculate the length of the pipe.(take pie = 3.14)

Answer 1

$$\begin{gathered} Arec\tan gularslabhasbeencastintotheshapeofironpipe \\ DimensionsofRec\tan gularslab=60cm\times 20cm\times 28.26cm \\ Dimensionsofironpipe, \\ width=1cm \\ outerdiameter=10cm \\ Outerradius\hspace{0.17em}\left(R\right)=5cm \\ Innerradius\left(r\right)=R-width=5-1=4cm \end{gathered}$$
$$\begin{gathered} Letthelengthofwirebeh \\ Volumeofslab=60cm\times 20cm\times 28.26cm \\ Volumeofironpipe=\mathrm{\pi }({\mathrm{R}}^2-{\mathrm{r}}^2)\mathrm{h}=3.14(5^2-4^2)\mathrm{h} \\ =3.14(25-16)\mathrm{h}=3.14\times 9\times \mathrm{h} \\ \mathrm{Volume}\mathrm{of}\mathrm{iron}\mathrm{slab}=\mathrm{volume}\mathrm{of}\mathrm{iron}\mathrm{pipe} \\ 60\mathrm{c}\mathrm{m}\times 20\mathrm{c}\mathrm{m}\times 28.26\mathrm{c}\mathrm{m}=3.14\times 9\times \mathrm{h} \\ \mathrm{h}=\frac{60\times 20\times 28.26}{3.14\times 9}=1200\mathrm{cm}=12\mathrm{m} \end{gathered}$$