What is the frictional force exerted by the fluids also called?

RRB Nsg. Superintendent 21 July 2019 (shift 1st)

Edition 3

Easy

Appeared in: RRB Nsg. Superintendent 21 July 2019 (shift 1st)

Explanation

The correct term for the frictional force exerted by fluids (liquids and gases) that opposes the motion of an object is 'Drag'.
This resistive force is a fundamental concept in fluid dynamics.
The amount of drag depends on factors like the object's speed and shape, and the fluid's viscosity.
For example, a streamlined object experiences less drag than a blunt object at the same speed.

Option A: Slag is a term from metallurgy, referring to the waste product from smelting ore. It is completely unrelated to physics or fluid forces.
Option B: Effort is the input force applied to a simple machine (like a lever or pulley) to overcome a resistance (the load). It is an applied force, not a resistive frictional force.
Option D: Core refers to the central part of an object or concept (e.g., Earth's core, core muscles). It does not describe a type of physical force.

Visual 1: Diagram - An illustration showing a sphere moving through a fluid. Arrows should indicate the direction of motion and the opposing drag force vector. This helps visualize that drag always opposes motion.
Visual 2: Infographic - A comparison of drag on a streamlined object (like a fish or airplane wing) versus a non-streamlined object (like a flat plate), demonstrating how shape affects the magnitude of drag force.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Fluid Dynamics and Frictional Forces as background academic context rather than a clinical decision trigger.
While 'drag' is a physics term, the underlying principle of friction is highly relevant in nursing. For instance, friction is the force that opposes movement when two surfaces are in contact, which can lead to skin injuries like 'sheet burn' if a patient is dragged across bed linens.
In the body, fluid friction (drag) is a key factor in blood circulation. The resistance that blood vessels offer to blood flow is a form of drag. Conditions like atherosclerosis increase this resistance, raising blood pressure.
The body naturally uses fluids to reduce friction. Synovial fluid in joints and pleural fluid in the chest cavity act as lubricants to minimize friction and prevent tissue damage during movement.

How to Approach the Question

First, identify the key concepts in the question: 'frictional force' and 'fluids'.
This is a definition-based recall question. Your task is to remember the specific scientific term for this phenomenon.
Evaluate each option based on your knowledge of basic physics and general science.
Eliminate options that are clearly from different, unrelated fields (like 'Slag' from metallurgy and 'Core' from general vocabulary).
Differentiate between the remaining physics terms. 'Effort' is an applied force, while the question asks for a resistive (frictional) force.
Select 'Drag' as it is the precise term for friction in a fluid medium.

Concept Tested & Keywords

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