Lesson 6. Incomplete Model: Motion of the Moon with Solar Perturbation

Stephen Dickman, Jacob Kelter
Physics
Estimated time for students: one 45 minute period.
AP Physics 1
v3

Overview

This imperfect model attempts to show the Moon's orbit as it is being perturbed by the Sun. The student will have to state why the model does not accurately simulate the Lunar orbit as the Moon will leave its orbit about the Earth.

Standards

Computational Thinking in STEM 2.0
  • Computational Modeling and Simulation Practices
    • [CT-MODEL-1] Using computational models to understand a complex phenomenon
    • [CT-MODEL-2] Using computational models to hypothesize and test predictions
    • [CT-MODEL-3] Using a computational tool to understand a system's compenents and dynamics
Next Generation Science Standards
  • Physical Science
    • [HS-PS2-1] Analyze data to support the claim that Newton’s second law of motion describes the mathematical relationship among the net force on a macroscopic object, its mass, and its acceleration.
    • [MS-PS4-2] Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.

Credits

This model was created by Jacob Kelter and Stephen Dickman

Activities

  • 1. Sun/Earth/Moon Model- Not to scale.

Student Directions and Resources


Learning Objectives

  • Learn that the Moon is also affected by the Sun during it motion about the Earth.
  • Learn how complicated the "3 Body Problem" is.
  • Learn how changing initial condictions can greatly change the outcomes of motion.
  • Gain a deeper understanding of "negative energy".

1. Sun/Earth/Moon Model- Not to scale.


Run the simulation and see what happens. You will have to increase the speed of the model. Change the intial(vx) velocity of the Moon and repeat.


Question 1.1

What do you notice the or of the Moon doing? What is this effect called?



Question 1.2

State why you believe the orbit of the Moon is doing this?



Question 1.3

Sketch all the force and velocity vectors on the Moon at 12, 3, 6 and 9 o'clock. Point out where a new, full and half-moon would be.

Note: Draw your sketch in the sketchpad below


Question 1.4

Eventually, the Moon will fly away from the Earth, what did it gain in order for this to happen? Thus, why is the model imperfect?



Question 1.5

Why do the graphs show negative energy? Why do these graphs oscillate? Do they make sense?



Question 1.6

Coding Question:

Try to make a plot of the angular momentum of the Moon about the Earth. What should this plot exhibit? You need to look into the code for this.

Note: Draw your sketch in the sketchpad below