PhysicsScalar QuantityNCTB পদার্থবিজ্ঞান অধ্যায় ৪ (কাজ, ক্ষমতা ও শক্তি)
Work
Bengali: কাজ•Pronunciation: ওয়ার্ক•Symbol: W
Standard Definition:
The scalar product of the applied force vector and the displacement vector.
📐 Mathematical Equation, Units & Dimensions
Defining Mathematical Equation
Standard SI Unit
J (Joule) or N*m($J$ (জুল) বা $N\cdot m$)
Dimensional Analysis
CGS Unit
erg (আর্গ)
📖 Physical Concept & Comprehensive Explanation
In physics, work requires displacement along or against the direction of the applied force. If force and displacement are perpendicular (theta = 90 deg), work done is zero (termed a no-work force, such as centripetal force in circular orbits).
🎯 High-Yield Revision Points
- ✓Work is a scalar quantity.
- ✓Positive when motion aligns with force, negative when opposing.
- ✓Zero work when force is perpendicular to displacement (theta = 90 deg).
- ✓1 Joule = 10^7 ergs.
Use Online Solver for Work
Compute step-by-step solutions, verify formulas, and plot interactive diagrams on biggan.me.
❓ Frequently Asked Exam Questions (FAQ)
Common questions in board and competitive entrance examinations
Q1: Define 1 Joule of work.
One Joule is the work done when an applied force of 1 Newton causes a displacement of 1 meter in the direction of the force.
Q2: What is a no-work force? Give an example.
When applied force is perpendicular to displacement, work done is zero. Earth orbiting the Sun under centripetal gravity is a classic example.