# Ch 3: Energy, Work & Power in Physics

### About This Chapter

## Energy, Work & Power in Physics - Chapter Summary

This chapter will define what physics calls work, show you how to calculate it, and explain work's relationship with variable force. The specifics needed to define and calculate power are also presented. You will be introduced to the concepts of kinetic energy, potential energy, elastic potential energy and gravitational potential energy.

Our instructors will explain the differences between conservative and nonconservative forces, as well as how mechanical energy obeys the law of conservation of energy. The work-energy theorem will be introduced with explanations about its applications. Once you have completed this lessons, you should be able to:

- Define work using the rules of physics
- Calculate variable forces
- Use work and time to calculate power
- Differentiate between kinetic and potential energy
- Explain gravitational potential with examples
- Tell if a force is conservative or nonconservative
- Understand how mechanical force is transferred and converted
- Apply the work-energy theorem to various situations

Our professionally-designed lessons and quizzes are mobile-friendly and available for you to review at any time. Each lesson is accompanied by a printable transcript so you can study the material offline as well. The lesson quizzes and chapter tests help you gauge how well you understand the topic and if you need to review parts of the lesson again. If you have questions about the lesson, contact one of our instructors for help.

### 1. Work: Definition, Characteristics, and Examples

Pushing a wall all day may feel like work, but unless you get that wall moving you're not doing any work according to the rules of physics. In this video lesson, you'll learn how work is defined as well as how to calculate the amount of work done on an object.

### 2. Work Done by a Variable Force

Doing work on an object is a simple concept: we apply a certain force over a certain distance. But in real life, that force is rarely constant. Therefore, we need to understand variable forces and be able to calculate them accurately.

### 3. Power: Definition and Mathematics

Work involves moving an object with a force, but power tells us how quickly that work is done. In this lesson, you will learn about how power depends on both work and time as well as see examples of how to calculate power.

### 4. Kinetic Energy to Potential Energy: Relationship in Different Energy Types

This video defines and describes kinetic and potential energy. You'll learn how different types of energy can be classified as potential and kinetic. You'll also find out how kinetic and potential energy are transformed.

### 5. Elastic Potential Energy: Definition, Formula & Examples

Discover what elastic potential energy is and the types of objects that can have it. Then learn how we find the formula for elastic potential energy using a spring.

### 6. Gravitational Potential Energy: Definition, Formula & Examples

In this lesson, you will learn what gravitational potential is, the equation we use to calculate it, and how to use that equation. We'll look at some real-life examples so you can see how it works. A short quiz will follow.

### 7. Conservative Forces: Examples & Effects

Learn how to tell if a force is conservative and what exactly is being conserved. Then look at a couple of specific examples of forces to see how they are conservative.

### 8. Nonconservative Forces: Examples & Effects

Find out what exactly it is that makes a force nonconservative. Then look at some of the most common types of nonconservative forces and how they affect the world around us.

### 9. Conservation of Mechanical Energy

Energy comes in many forms and for any system can never be created or destroyed. This holds true for mechanical energy, which also obeys this law of conservation of energy. In this video lesson, you'll explore how mechanical energy is converted or transferred between forms and objects.

### 10. Work-Energy Theorem: Definition and Application

Work and energy are closely related in physics. In this lesson, you'll learn what that relationship is as well as how we can apply it to various situations.

### Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

### Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

### Other Chapters

Other chapters within the UPSEE Paper 1: Study Guide & Test Prep course

- Basics of Scientific Units & Measurement
- Understanding the Laws of Motion
- Fundamentals of Linear Momentum
- Understanding Rotation of a Rigid Body
- Gravitation in Physics
- Understanding Oscillatory Motion
- Mechanics of Solids & Fluids
- Properties of Heat & Thermodynamics
- Overview of Waves
- Understanding Electrostatics
- Overview of Current Electricity
- Magnetic Effect of Current
- Magnetism in Matter
- Electromagnetic Induction Overview
- Ray Optics & Optical Instruments
- Understanding Wave Optics
- Overview of Modern Physics
- Overview of Nuclear Physics
- Electronics, Transistors & Signals
- Atomic Structure & Configuration
- Properties of Chemical Bonds
- Redox Reactions Overview
- Chemical Equilibrium & Kinetics
- Electrochemistry & Catalysts
- Colloids in Chemistry
- Colligative Properties of Solution
- Periodic Table & Electronic Configuration
- Overview of Thermochemistry
- Reactions & Compounds in Organic Chemistry
- Understanding Isomerism
- Overview of Organic Compounds
- Properties of Solids in Chemistry
- Overview of Algebra Basics
- Matrices in Algebra
- Probability in Math
- Understanding Trigonometry
- Overview of Coordinate Geometry
- Principles of Calculus
- Vectors in Algebra
- Mechanics Overview
- UPSEE Paper 1 Flashcards