Module 6—Work and Energy
Lesson 3—Mechanical Energy and the Work-Energy Theorem
Get Focused
Downhill skiing in the mountains is made easier by the chairlift. Without it, very few people would ever have a chance to experience skiing at altitudes high enough to be in the clouds. Think about how much fun you would have if you had to hike up the mountainside—it would be a lot of work packing yourself and all your ski gear up the side of mountain in waist-deep snow!
While some people do choose other ways to get up to the top of the mountain, most skiers choose the chairlift as their energy source. It works against Earth’s gravitational field, moving uphill at a constant speed, from the bottom to the top. It also works against the force of friction, which acts whenever the chairlift is in operation. Given these facts, how does the work done by the chairlift relate to the gain in the mechanical energy of the skiers and the work done to overcome friction?
In this lesson you will explore the following questions:
- How do you know how much work is done by a chairlift?
- What effect do conservative and non-conservative forces have on the gain in mechanical energy of the skiers on the lift?
- What is the work-potential energy theorem?
Module 6: Lesson 3 Assignments
Your teacher-marked Module 6: Lesson 3 Assignment requires you to submit a response to the following:
- Lab—LAB 1, LAB 2, LAB 3, LAB 4, LAB 5, LAB 6, LAB 7, LAB 8, LAB 9, LAB 10, and LAB 11
- Try This—TR 1
- Discuss—D 1 and D 2
You must decide what to do with the questions that are not marked by the teacher.
Remember that these questions provide you with the practice and feedback that you need to successfully complete this course. You should respond to all the questions and place those answers in your course folder.