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Dimensions of a solid cuboid are 4.4 m, 2.6 m and 1 m. It is melted and recasted into ahollow cylindrical pipe of inner radius of 30 cm and outer radius of 35 cm. Find the lengthof the pipe. |
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Answer» Length , l = 4.4 metres Breadth , b = 2.6 metres Height , h = 1 metre Volume of a cuboid = l b h = 4.4 × 2.6 × 1 = 11.44 m³ The cuboid is melted and is made into a hollow cylindrical pipe. But , Even if shape changes ,Volume of both the shapes remains same. Volume of cuboid = Volume of hollow cylindrical pipe = 11.44 m³ ================================== Radius ,r = 30 cm = 0.3 metres Thickness = 5 cm = 0.05 metre Outer radius, R = inner radius + thickness= 0.3 + 0.05= 0.35 metres Height of the pipe = Length of the pipe Volume of a cylindrical pipe = π [ R² - r ² ] × h=22/7× [ (0.35)² - (0.3)² ] ×h 22/7× [ (0.35)² - (0.3)² ] ×h = 11.44 m³ 22/7× [ 0.1225 - 0.09 ] ×h = 11.44 m³ 22/7× 0.0325 × h = 11.44 m³ h =11.44*7/22*0.0325 =80.08/0.715 = 112 metres Length of the pipe = 112 metres |
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