# HP Cycle 24

## 2/3 - 2/8

Th 2/3

F 2/4

M 2/7

T 2/8

### π’ 6: Th 2/3, π΅ 8: Th 2/3 - uniform circular motion problems

Today, we'll spend time working through some circular motion example problems:

Vertical circles are an example of where gravity combines with some other force to account for the centripetal force. Remember "centripetal force" is another word for NET force when going in a circle.

With any remaining time, you may start β Positive Physics circular motion problems from the next post.

Optional Extra Practice: If you need extra practice on easy UCM problems, Circular Motion Practice worksheet (optional) (Ans: 1. (a) 8.77m/s2 (b) mass times 1a. 2. (a) 1.56m/s (b) mass times 8.11m/s2 (c) 8.11m/s2. 3. (a) 0.650 (b) no change. Hard Circular Motion Problems. (skip #9) ANSWERS. - note: for #3a, an acceleration of β1gβ is 9.8 m/s2, so an acceleration of 0.050g is (0.050)(9.8 m/s2).

Homework: If you missed class or would like to review, check out these videos on vertical circles:

### π© 6: M 2/7, π¦ 8: F 2/5 - β Positive Physics circular motion problems

Today, we'll start class with one quick Orbit Problem, which combines the ideas of uniform circular motion with universal gravitation. If you missed the lecture or need a refresher, watch this video.

Then, we'll do β Positive Physics "work" problems from unit 10: circular motion:

• complete problems 1

• complete problems 2

• complete problems 3

Also do β Positive Physics "work" problems from unit 11: universal gravitation:

• orbit problems

Homework: β Positive Physics unit 10/11 problems due Tuesday at 10pm. Only completion score will count, so keep trying the problems until you get them correct. No late work will be accepted. Assessment on Gravitation and Circular Motion on Friday, February 11th. (postponed from Wednesday)

### π 6: T 2/8, π 8: M 2/7 - "work"

The concept of βworkβ 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: Finish page 1 in Work & Energy Packet. (Unit 6 CompuSheets Answers)

Homework: Assessment on Gravitation and Circular Motion on Friday, February 11th.