The length of a metallic pipe is 7.56 m. Its external and internal radii are 2.5 cm and 1.5 cm respectively. If 1 cm of the metal weight 7.5 g, then the weight of the pipe is : (Take π = 22/7)
Show answer & explanation
Correct answer: D
Explanation
Correct Answer is option 4 i.e. 71.28 Kg
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Concept |
Understanding |
Application |
Fair calculation |
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Volume of pipe = π (R2 - r2) × L |
Length of metallic pipe = L = 7.56 m = 756 cm Outer radius = R = 2.5 cm Internal radius = r = 1.5 cm |
Volume of pipe = 22/7 × L × (R + r) (R – r) = 22/7 × 756 × 4 × 1 = 9504 cm3 Weight of 1 cm3 volume of metal = 7.5 gm So, Weight of pipe = 7.5 × 9504 gm = 71.28 Kg |
22/7 × 756 × 4 × 1 = 88 × 108 = 9504 |