Questions

A number of possible explanations for why manhole covers are round include :

1. A round manhole cover cannot fall through its circular opening, whereas a square, rectangular, or oval manhole cover could fall in if it were inserted diagonally in the hole.

2. Circular covers don’t need to be rotated or precisely aligned when placing them on the opening.

3. A round manhole cover is easily moved and rolled.

4. Human beings have a roughly circular cross-section.

5. Round tubes are the strongest shape against the compression of the earth around them, so the cover of the tube would naturally be round as well.

6. It’s easier to dig a circular hole.

Life Cycle costing includes the costs from each phase of the project life cycle when the total investment costs are calculated. Answer A is incorrect because an opportunity cost is the difference between a chosen investment and the one that is passed up. Answer B is incorrect because sunk costs are costs that have been incurred and cannot be reversed. Answer C is incorrect because net present value (NPV) is the present value of cash inflows(benifits) minus the present value of cash outflows (costs).

The acid used in lead storage cells is Sulphuric acid. They are used car batteries. Lead-acid batteries are capable of being recharged, which is important for their use in cars.

Latitude of place is indicative of its temperature. In geography, latitude is a geographic coordinate that specifies the north–south position of a point on the Earth's surface. Latitude is an angle which ranges from 0° at the Equator to 90° at the poles.