HP Cycle 19
1/2 - 1/5
T 1/2
W 1/3
Th 1/4
F 1/5
🟢 5: T 1/2 - 📄dynamics review
During sub study today, do a few problems which will require you to remember everything you have learned so far this year. The please read the directions on page 1 carefully. Find help if you need it. This assignment will be graded as an "assessment" of what you know so far. You will be asked to redo problems until the work, final algebraic expression, and numerical answer are correct for all problems.
Handout: Dynamics & Energy Conservation Problems
Homework: These problems will be collected at the beginning of class on Wednesday, January 3rd.
🟩 5: W 1/3 - "work"
The concept of “work” is slightly different than the definition we use in every day life. Today, we will review how to calculate work and how this relates to the concept of energy. We will also define gravitational potential energy as well as kinetic energy, and derive equations for both.
Presentation: Work & Energy Presentation (we will try to get through slides 1-22 today)
Optional Extra Practice: Page 1 in Work & Energy Packet. (Unit 6 CompuSheets Answers)
Homework: Make sure to understand all of the concepts and formulas presented this class.
💚 5: F 1/5 - ↩️Pivot pendulum energy lab (1)
Today, we'll do a lab where we investigate how work and energy are related. You'll observe how energy transformations occur in a simple pendulum. You'll learn to use a Vernier photogate timer to find the velocity of the pendulum. The directions for the lab and write-up are located in ↩️ Pivot Interactives "Pendulum Energy Lab." Here's the setup:
Raise the pendulum mass to a height above its lowest (equilibrium) position. Release and measure the velocity as it passes through its lowest position. Repeat for at least 6 different release heights. Graph velocity (m/s) vs. release height (m). Find the mathematical relationship (equation) between velocity and release height, linearizing the graph if necessary.
Analysis question include:
How much work do you do in raising the the pendulum mass?
What forces are on the pendulum as it swings down to equilibrium position? (Draw a free body diagram.) How much work does each of the forces do?
Write a sentence or two about how mechanical energy is transformed from one form to another.
Describe the shape of the velocity vs. height graph. What does this say about the relationship between velocity and release height.
What is the theoretical value of the coefficient in your equation? How does it compare with your experimentally found coefficient?
What assumptions did you make in your experiment? How would these assumptions affect your coefficient that you found in your mathematical relationship?
What is the role of the mass of the pendulum in your equation? Would a better determination of the value of this mass improve the accuracy or precision of this experiment?
Homework: Pendulum energy lab is due in ↩️ Pivot Interactives is due Thursday, January 11th at 10pm. Pendulum Lab assessment Friday, January 12th.