Questions

Answer D is correct because a sunk cost is a project expense that will eventualy need to be paid. Answer A is incorrect because a fixed cost remains constant, regardless of any change in a company's activity. Answer B is incorrect because direct cost can be directly linked to producing specific goods or services. Answer C is incorrect because a variable cost changes in proportion to a change in the company's activity or business.

It will stop at a height where the weight of the balloon with contents is equal to the weight of air displaced by it, i.e , when the upthrust is equal to the downthrust. The question of bursting will depend on how much difference of pressure inside and outside , the material of the balloon can withstand. It is assumed the balloon is filled with a lighter than air gas like hydrogen or helium.

$pwd - present working directory

Donna Tratt

Passivity of iron is due to formation of an extremely thin and impervious film of ferrosoferric oxide Fe3O4on the surface of iron. Chromic acid, being a powerful oxidising agent (like nitric acid ) renders iron passive.