Ch 21: Work & Energy in Physics

About This Chapter

Watch these video lessons to learn about the relationship between work and energy. Get information on the work-energy theorem, conservation of mechanical energy and the definition of power.

Work & Energy in Physics - Chapter Summary

This chapter's lessons look at energy and work, and how they are related. Our instructors will give definitions of both terms, and explain the work-energy theorem and its application. You'll learn about work done by a variable force and get information on conservative forces.

Other lessons look at kinetic and potential energy and mechanical energy. You'll also learn the definition of power. After completing these lessons, you'll be capable of:

  • Stating the role of energy in nature
  • Defining and giving characteristics of work
  • Describing work done by a variable force
  • Explaining the work-energy theorem
  • Showing the relationship of kinetic and potential energy
  • Giving examples of conservative forces
  • Defining conservation of mechanical energy
  • Performing calculations regarding power

These lessons and quizzes are developed and presented by experts who make learning informative and enjoyable. After assessing your knowledge with the quizzes at the end of each lesson, you can use video tags to go back and find concepts that need further review. If you still have some questions, you may reach out to your instructor for help.

8 Lessons in Chapter 21: Work & Energy in Physics
Test your knowledge with a 30-question chapter practice test
What is Energy? - Definition and Significance in Nature

1. What is Energy? - Definition and Significance in Nature

This lesson describes the nature of energy and how it is transferred from one source into another. Additionally, it will describe the significance of energy in natural systems.

Work: Definition, Characteristics, and Examples

2. 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.

Work Done by a Variable Force

3. 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.

Work-Energy Theorem: Definition and Application

4. 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.

Kinetic Energy to Potential Energy: Relationship in Different Energy Types

5. 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.

Conservative Forces: Examples & Effects

6. 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.

Conservation of Mechanical Energy

7. 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.

Power: Definition and Mathematics

8. 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.

Chapter Practice Exam
Test your knowledge of this chapter with a 30 question practice chapter exam.
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Practice Final Exam
Test your knowledge of the entire course with a 50 question practice final exam.
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