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A solid right prism made of iron has cross section of a triangle of sides 5cm, 10cm, 13cm and of height 10 cm. If one cubic cm of iron weights 7g, then the weight of the prism is (approximately)
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- 1570.8 gram
- 1371.32 gram
- 1470.8 gram
- 1100.68 gram
- 1570.8 gram
Correct Option: A
The base of a prism is a triangular.
Semi-perimeter of triangle(s)
| = | = | = 14cm. | ||
| 2 | 2 |
∴ Area of triangle = √s(s - a)(s - b)(s - c)
= √14(14 - 5)(14 - 10 (14 - 13)
= √14 × 9 × 4 × 1
= 6 √14 cu.cm.
= ∴ Volume of prism = Area of base × height
= 6 √14 × 10 = 60√14cu.cm.
= 60 × 3.742 = 224.52 cu.cm.
∴ Weight of the prism = (224.52 × 7) gram = 1571.64 gram
