हिंदी

Below are the drawings of cross sections of two different pipes used to fill swimming pools. Figure A is a combination of 2 pipes each having a radius of 8 cm.

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प्रश्न

Below are the drawings of cross sections of two different pipes used to fill swimming pools. Figure A is a combination of 2 pipes each having a radius of 8 cm. Figure B is a pipe having a radius of 15 cm. If the force of the flow of water coming out of the pipes is the same in both the cases, which will fill the swimming pool faster?

योग
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उत्तर

In figure A, 2 pipes each having a radius of 8 cm

∵ Area of a circle = πr2

∴ Area of one pipe = `22/7 xx 8 xx 8`

= `(22 xx 8 xx 8)/7`

= `(22 xx 64)/7` cm2

Area of 2 pipes = `(2 xx 1408)/7`

= `2816/7` cm2

= 402.28 cm2

In figure B, a pipe having radius of 15 cm

∴ Area of the pipe = πr2

= `22/7 xx 15 xx 15`

= `22/7 xx 225`

= `4950/7`

= 707.14 cm2

Clearly, the surface area of pipe B is greater. So, pipe B fills the swimming pool faster.

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अध्याय 11: Mensuration - Exercise [पृष्ठ ३५७]

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एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 8
अध्याय 11 Mensuration
Exercise | Q 104. | पृष्ठ ३५७

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