Work, Energy & Power Basics

Work, Energy & Power Basics – Physics 2026

Work, Energy and Power is one of the most important chapters in Physics. It builds the foundation for mechanics, rotational motion, and modern physics.

Work Energy and Power
Work Energy and Power

At CHEMASH, this chapter is taught with real-life understanding, problem-solving practice, and exam-oriented concepts for Class 9–12, JEE & NEET 2026.


Table of Contents


1️⃣ What is Work?

In Physics, work is said to be done when a force causes displacement.

Formula:
W = F × s × cosθ

  • F = Force
  • s = Displacement
  • θ = Angle between force and displacement

Unit: Joule (J) Dimension: [ML²T⁻²]

Important Concept:

  • Positive Work → Force and displacement same direction
  • Negative Work → Opposite direction
  • Zero Work → No displacement

2️⃣ What is Energy?

Energy is the capacity to do work.

Energy can neither be created nor destroyed — only transformed. (Conservation of Energy)


3️⃣ Types of Energy

Kinetic Energy

Energy due to motion.

KE = ½mv²

Potential Energy

Energy due to position.

PE = mgh


4️⃣ What is Power?

Power is the rate of doing work.

P = Work / Time

SI Unit = Watt (W)


5️⃣ Important Formula Table

ConceptFormula
WorkW = Fs cosθ
Kinetic EnergyKE = ½mv²
Potential EnergyPE = mgh
PowerP = W/t

6️⃣ Real-Life Examples

  • Lifting a bag → Work done against gravity
  • Moving car → Kinetic energy
  • Water stored in dam → Potential energy
  • Electric motor → Converts electrical energy to mechanical energy

7️⃣ Solved Numerical (Exam Level)

Q: A force of 10 N moves an object by 5 m in same direction. Find work done.

W = F × s = 10 × 5 = 50 Joules


8️⃣ MCQs (Boards + JEE + NEET)

1. Unit of Power is: A) Joule B) Newton C) Watt ✔ D) Pascal

Explanation: Power = Work/Time, SI unit = Watt.


9️⃣ Frequently Asked Questions

Is Work Energy Power important for JEE 2026?
Yes, it is a core mechanics chapter with conceptual and numerical questions.

Does CHEMASH provide practice problems?
Yes, we focus strongly on numericals and concept clarity.


Why Study Physics with CHEMASH?

  • Low-budget tuition for all classes
  • Experienced and supportive teachers
  • Strong concept + numerical approach
  • Trusted by students and parents
  • Board + JEE + NEET preparation

Internal Link: Laws of Motion – CHEMASH

External Reference: Energy Concepts – Physics Classroom

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