# HP Cycle 26

## 2/15 - 2/19

T 2/15

W 2/16

Th 2/17

F 2/18

### π’ 6: T 2/15, π΅ 8: T 2/15 - conservation of energy examples

Today, we'll discover the interesting thing about the conservation of energy by doing a few problems which will require you to remember everything you have learned so far this year. We will learn that there are usually a few different ways of solving physics problems - with forces and kinematics or with work and energy. We will discover when it is best to use either strategy. We'll also learn how to use "before and after" diagrams.

With the time remaining, you'll think in your lab groups about how what we learned can be applied to complete your β©οΈ Pivot Interactives lab "Height vs Velocity for a Puck on a Ramp" is due tonight at 10pm.

Presentation: Conservation of Energy Examples (we'll focus on slides 1-11)

Homework: β©οΈ Pivot Interactives lab "Height vs Velocity for a Puck on a Ramp" is due tonight Tuesday at 10pm.

Optional Extra Practice: Work & Energy Packet - page 3 only (Unit 6 CompuSheets Answers)

### π© 6: Th 2/17, π¦ 8: W 2/16 - work by non-conservative forces

Today, we will look at some problems where we can use our knowledge of kinetic and gravitational potential energy to solve complex kinematics problems. Conservation of energy is a useful tool and a alternative to using Newton's Laws and kinematics. Remember that work and energy are scalar quantities.

Presentation: Conservation of Energy Examples (we'll focus on the last two slides)

Optional Extra Practice: Work & Energy Packet page 4 #1-5 (Solutions to FYP: Energy).

Homework: Review your notes and write down any questions you have. Try some of the optional extra practice. Quiz on simple energy conservation problems (no friction) on Monday, February 21st.

### π 6: F 2/18, π 8: Th 2/17 - β Positive Physics energy (2)

Today, we'll start with a discussion about Energy Bar Charts. This is an option if you prefer these to Before & After Diagrams.

Then, we'll practice all we've learned about work and energy by doing β Positive Physics unit 13: energy "work" problems from the following sections:

• complete problems 1

• complete problems 2

• complete problems 3

NOTE: Positive physics uses some unconventional vocabulary:

• "KE" is kinetic energy (K).

• "GPE" is gravitational potential energy (Ug).

• "EPE" is elastic potential energy (Ue).

• "work" means POSITIVE work done by a non-conservative force.

• "loss" means NEGATIVE work by a non-conservative force.

Homework: Finish these problems by Sunday at 10pm. Only completion score counts. No late work will be accepted. Quiz on simple energy conservation problems (no friction) next class - Monday, February 21st.

Optional Extra Practice: so far...