# HP Cycle 15

## 12/3 - 12/8

F 12/3

M 12/6

T 12/7

W 12/8

### π’β 6: F 12/3, π΅β 8: F 12/3 - β Positive Physics systems

QUIZ on Friction Today!

After the quiz, in order to reinforce the problem-solving techniques for multiple objects in a system, we'll work on β Positive Physics problems from unit 7: systems "work" section (11 problems total):

• complete problems 1 (skip #6)

• complete problems 2

• complete problems 3

Homework: Above problems are due on Sunday, December 5th at 10pm. Remember with β Positive Physics, no late work will be accepted so don't procrastinate.

### π© 6: T 12/7, π¦ 8: M 12/6 - intro to vectors

Today, we'll see how we can add vectors that are not at right angles to each other. We will learn to break vectors into x- and y- components and why that is useful to us.

Then, we'll practice taking vector components in β Positive Physics. We'll do "work" problems from unit 8: diagonal forces (11 problems total):

• free body diagram drawing

• trigonometry

Homework: Assessment of all of Newton's Laws in 1-D next Monday, December 13th. These β Positive Physics problems are due Thursday, December 9th at 10pm. Only completion score counts, and no late work accepted. If you'd like to review more on vector addition, you can watch these videos:

### π 6: W 12/8, π 8: T 12/7 - static equilibrium lab

Today, we'll look at "static equilibrium" problems - where the forces are balanced. We'll look at how Newton's Second Law acts in two dimensions by performing a lab where we try to find the mass of a mystery object using two dimensional forces. See the figure for set-up of the "y-tension problem." In these types of problems, we'll look at making Ξ£Fx=0 and Ξ£Fy=0, but some of the forces will be at angles.

If you have any trouble understanding the calculations here, check out the following video below. The strategy is to draw a free body diagram of the knot. (If the knot is made out of ideal or massless string, it does not have a force of gravity on it.)

Homework: Assessment of all of Newton's Laws in 1-D next Monday, December 13th. Lab quiz on Y-Tension problem on Wednesday, December 15th.