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How much iron is needed to make a rod of length 90 cm and diametar 1.4 cm? |
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Answer» Length of rod , l = 90 cm diameter of rod , d = 1.4 cm so, radius of rod , r = 1.4/2 = 0.7 cm volume of rod = πr²l = 22/7 × 0.7 × 0.7 × 90 = 22 × 0.1 × 0.7 × 90 = 22 × 0.7 × 9= 198 × 0.7 = 138.6 cm³ hence, 138.6 cm³ iron is needed to make a rod of length 90 cm and diameter 1.4 cm. |
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