Honors Physics‎ > ‎

How do we solve complex work and energy problems?

posted Feb 5, 2020, 5:31 AM by Barbara Fortunato
6: Th 2/6, 8: Th 2/6

Today, we’ll tackle some more challenging work & energy problems in lab groups. What you should focus on is drawing your before & after diagrams. Although many of these problems can be solved with kinematics, it's often easier to solve them with energy.  As much as you are tempted to fall back on solving with forces, strengthen your skill by solving with work and energy.

Solve problems from Energy Text Worksheets side B (page 2).  If you finish, you can start on Work, Energy, and Power Review Problems page 2 only.

HandoutEnergy Text WorksheetsWork, Energy, and Power Review Problems.
HomeworkEnergy Text Worksheets - Try to finish all of side B, but at least do up to #8.  Make sure you have a before and after diagram for each problem... a before and after diagram labels what kinds of energy exist at the beginning and at the end, it's not just a picture of the problem.  Don't forget to label where Ug = 0 in your diagram.  Then write a statement of conservation of energy.  
SolutionsCheck out my solutions to ETW-B!  In #1, I should have written that the work done by the resistive force of the water was F h2cosθ, and since θ should have been 180 degrees, the answer F should have been positive (actually just a magnitude) and pointing up.  Also, ETW-A #5 solution.