According to Archimedes principle, the upward force acting on a body that is wholly or partly immersed in a fluid is called what?

Introduction / Context:

This question is from fluid mechanics and tests knowledge of the basic term used for the upward force experienced by a body immersed in a liquid or gas. Archimedes principle explains why objects float or sink and is widely applied in ship design, hydrometers, and many practical situations. Knowing the correct name of this upward force is important for understanding floating bodies and related calculations.

Given Data / Assumptions:

• A body is wholly or partly immersed in a fluid such as water or air.
• An upward force from the fluid acts on the body.
• We are asked for the standard term used to describe this upward force.
• Archimedes principle and basic fluid concepts are assumed.

Concept / Approach:

Archimedes principle states that a body immersed in a fluid experiences an upward force equal to the weight of the fluid displaced by it. This upward force is called buoyant force, and the effect is called buoyancy. This force acts opposite to the weight of the body and is responsible for floating and sinking behaviour. The term jerk refers to the rate of change of acceleration, anti gravity is a speculative or science fiction idea, and Archimedean force is not the standard textbook term, even though it refers to the same concept informally. The accepted term is buoyancy or buoyant force.

Step-by-Step Solution:

Verification / Alternative check:

Examples include ships that float because the buoyant force balances their weight, and balloons that rise in air. Textbooks refer to the upward force as buoyant force and to the phenomenon as buoyancy. Hydrometers that measure relative density also rely on buoyant force. No text uses jerk or anti gravity as the name of this force. While the phrase Archimedean force might be used informally to honour Archimedes, it is not the standard term used in definitions or formulas.

Why Other Options Are Wrong:

• Jerk: A kinematics term meaning rate of change of acceleration, unrelated to floating objects in fluids.
• Archimedean force: Not a standard textbook term, even though it hints at Archimedes principle.
• Anti gravity: A popular term in science fiction, not a recognised force in elementary physics.

Common Pitfalls:

Learners sometimes choose anti gravity because it sounds like a force opposite to gravity. However, in real physics, the upward force in fluids is explained entirely by pressure differences and is called buoyant force. Another confusion arises from mixing the principle name with the force name and selecting Archimedean force. Remember that the principle is called Archimedes principle, but the force is called buoyant force and the effect is buoyancy.

Final Answer:

The upward force on a floating or immersed body is called buoyancy or buoyant force.