# HP Cycle 20*

## 1/10 - 1/13

M 1/10

T 1/11

W 1/12

Th 1/13

### π’ 6: M 1/10 virtual, π΅β 8: T 1/11 - friction and vector forces

Pd 8 only: Quiz on inclined planes (pulleys included) TODAY!

Today, we'll look at one other kind of problem - we pull or push a block at an angle. We'll see that when we do this, the normal force is NOT equal to the force of gravity! We'll try to finish Friction & Vector Forces during class. Watch the video...

Homework: Finish Friction & Vector Forces. (SOLUTIONS) Pd 6 only: Study for Quiz on inclined planes (pulleys included) next class - Tuesday, January 11th!

### π©β 6: T 1/11, π¦ 8: W 1/12 virtual - relative motion / boats

Pd 6 only: Quiz on inclined planes (pulleys included) TODAY!

Today, we'll use an in-class demonstration and this simulation to explore the concept of relative motion. We'll observe a model of relative motion in class, and then we will try to come up with a mathematical model (formula) to describe relative motion. We will learn how we can use our knowledge of vectors to determine the velocity of one object relative to another in two dimensions. We will convince ourselves of the independence of x- and y- components.

Presentation: Boat Problems PowerPoint (SOLUTIONS)
Homework: Watch the following videos on relative motion:

### π 6: Th 1/13, π 8: Th 1/13 - boat problems

Today, we'll finish the "boat problems" in Boat Problems PowerPoint (SOLUTIONS). Watch the following videos:

This first video is a review of what we learned in class previously:

This second video is a for solving for the angle of a moving object so that its resultant is a certain way.

Then, do the following problems on a separate piece of paper to be submitted Tuesday/Wednesday (whichever is the first day we are in person): Chapter 3 #68, 71-74, 78, 80, 82. Solutions.

Homework: Finish the above problems for in-class submission on Tuesday, January 18th if hybrid or Wednesday, January 19th if back to full in-person.