From the principle of flotation, a body sinks in a fluid until it displace a quantity equal to its own?

Analyze the question: It asks what quantity of fluid a floating body displaces, according to the principle of flotation.

Concept: The law of flotation says that a floating body displaces a weight of fluid equal to its own weight. It comes from Archimedes' principle, which says the upthrust on a body equals the weight of the fluid it displaces.

Step-by-step solution:

1. A body floats when it is in equilibrium. This means the upward force (upthrust) balances the downward force (the body's weight).
2. Upthrust = weight of fluid displaced.
3. For equilibrium, weight of body = upthrust.
4. Therefore, weight of body = weight of fluid displaced.

About the options:

• Density: Not a quantity that can be "displaced," so this is wrong.
• Mass: Mass of fluid displaced does equal the body's mass, since g cancels. This is true, but the principle is traditionally stated in terms of weight.

• Volume: The volume displaced equals the body's volume only when it is fully submerged. A floating body displaces less volume than its own, so this is wrong.

Answer: C. weight

Tip: Remember "Floating means weight equals weight," that is, the weight of the body equals the weight of the fluid displaced. In WASSCE, when both mass and weight appear as options, choose weight, because the principle is a statement about forces.