**Week 5:**

Universal Gravity, complicated kinematics

**Day 1: Universal Gravity and the Ubiquitous Inverse Square Law**__Before Class: See scaling and gravity video____From Textbook:__ Read the first half of section 6.5, up to (but not including) example 6.6, try the first two “section 6.5” problems at the end of chapter 6. These are problems 33 and 34 for me calculating the mass and acceleration of the earth respectively.__In class:__ Hand in PS #4, and be prepared to take a quiz on the ubiquitous inverse square law like the quiz given in the video.

**Day 2: Gravitational Energy and Escape Velocity**

__Before Class: See videos about Escape Velocity__

In class: Do “escape velocity problem” (part of PS #5)

**Day 3: Energy Diagrams**

Hand in Perfect Corrections for Midterm 1 with answers. For details, see Syllabus

See this video on Potential Energy Graphs**Next Problem Set: PS#5 is available on the main timeline:Main Timeline**

**Day 4: Projectile Motion: Complicated Kinematics and Projectile Motion**__ Textbook:__ Read and understand section 2.5. Read earlier sections of chapter 2 if you like

See this video Veritassium music video I’m always scared when someone uses the word “inertia” because it’s so often misused… “inertia” is just mass in that a = F/m, so as mass increases, acceleration decreases. You don’t really need to use the word “inertia”… but he does, so be careful!