In this lesson our instructor talks about work. First, he discusses equivocation and an introduction to work. The he talks about the definition, formula, and units for work. Five complete example problems round up this lesson.
The idea of work is deeply connected to the idea of energy, as we will see in coming lessons.
Qualitatively, you've done more work on an object if you push with more force than less force. Similarly, you do more work if you push for a longer distance than less distance.
We want to define work as how much change you put into the world. Even if an object moves a distance, your force has to have some effect on the object's motion. No effect, no work.
This means that if your force is perpendicular to the movement, it contributes nothing-no work.
Work is the distance traveled multiplied by the force parallel to the motion. If the angle between them is θ, we can use trigonometry to get
W = |
The unit for work is the newton·meter, which we call a joule (J).
Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.
This book includes a set of features such as Analyzing-Multiple-Concept Problems, Check Your Understanding, Concepts & Calculations, and Concepts at a Glance. This helps the reader to first identify the physics concepts, then associate the appropriate mathematical equations, and finally to work out an algebraic solution.