DAY 82
WARM-UP:
Working a COE problem
1. What does COE stand for?
2. Watch the video here --> LINK and answer the questions below and in the edpuzzle
A. Copy the work and solution steps in your notes
B. Is our answer a velocity? Why or why not?
C. Why can't we use projectile motion (x & y components, etc) to solve this problem?
D. Extra credit: Are you sure we can't use projectile motion?
CLASSWORK:
0. Review. Last class we:
- watched videos and made bar graphs showing energy transfer
- reviewed and used the problem solving strategy from page 295
- today we solved a problem together with Mr. P from Flipping Physics
1. HW Questions?
2. Conservation of Mechanical Energy Practice
Solve pg 297 18 & pg 308-309 73-77, 79, 79, 81
Your group will be assigned one problem to show/explain on the HoverCam projector
18: _________ 1.00m above platform
73: _________ a. 4.90x103 J b. 4.90x103 J c. 4.90x103 J
74: _________ a. 2x104 J b. 2x104 J c. 40m/s
75: _________ a. 42 m/s b. 8.9 x 101 m
76: __________ 407 J, 2.0 x 101 m/s
77: __________ 9.39 m/s
79: __________ 39.4m
81: __________ 4.1m/s
3. Collisions.
A. DEMO: What are the 3 types of collisions?
List the 3 types in your notes
B. Is Momentum Always Conserved?
Let's think... if the system includes the same two cars, before and after a collision, is momentum conserved?
...if the system includes the two cars before the collision, but a third car bumps car #2 after the collision, is momentum
conserved?
C. Is Kinetic Energy Always Conserved?
A. Calculate the KEi and KEf for Case 1, 2, and 3
B. Elastic Collisions
C. Inelastic Collisions
4. Example Collision Problem
In an accident on a slippery road, a compact car with a mass of 575 kg moving at 15.0 m/s smashes into the rear end of a car with mass 1575 kg moving at 5.00 m/s in the same direction.
a. What is the final velocity if the wrecked cars lock together?
b. How much kinetic energy was lost in the collision?
c. What fraction of the original kinetic energy was lost?
5. Practice Problems
Solve pg 300 19, 20
HOMEWORK:
Solve: pg 300 #21
For our last unit, we will study electronics and the circuits you use in your daily lives. Very enlightening... :-)
Watch: https://www.youtube.com/watch?v=-n1pSHzdahc
- Why does the polystyrene (foam) plate keep the "Brainiac" from getting electrocuted?
Read chapter 22, pages 590-594. Answer pg 594 1-2; pg 610 #39
- There may be a short reading quiz... :)
#Goals: SWBAT...
1. ... Describe the difference between Ohmic and non-Ohmic
2. ... Identify instruments and tools used in circuits
3. ... Solve problems involving current, potential, and power
WARM-UP:
Your warm-up will happen on the projector. Have the questions up on your computer.
Have your homework out so I can walk around and check it.
http://www.flippingphysics.com/introduction-to-conventional-current.html
0. What does "q" or "Q" stand for? What is the unit of q? What is I? What is the unit of I?
1. Why are the electrons the atomic components which flow, and not the protons?
2. Which way do electrons flow?
3. Why does that give us a positive direction of current flow?
4. Copy the current graphs.
A. Which do we use for long-distance electricity transmission?
B. Which do we use in our homes?
5. Copy the example problem
CLASSWORK:
1. P=IV Problem Example & Practice
- pg 594 Example Problem #1
- use river current example
- try problems 3-5 (6min)
2. Complete "The Tools of Electricity" (4 items x 5 min/item = 20 min)
For each item (1-6), individually complete the following...
Name:
Description of Physical Form:
How much it costs
Function:
30 second presentations:
1. Mayte Ariella
2. Jonathan Parker
3. Rosie El Presidente
4. Ricky Muscle Man Mena
5. Jesus Vanessa
6. Gerald Erik
3. Creating a Circuit
Review the Circuit Symbols Diagram
Complete the Launch Lab from pg 591. For your diagram, use the symbols you learned in your
homework.
(Save for next time) 4. Ohm's Law and Resistance Notes
- Definition:
- Examples of Resistance
Silver wire: 0.0000000159 ohm
Copper Wire: 0.0000000168 ohm
Car brake light: 3 ohm
Glass: 1,000,000,000 ohm
Rubber: 100,000,000,000,000 ohm
Your Mom: ∞
http://www.flippingphysics.com/defining-resistance.html
4. pg 598 6-7. Sketch the diagram, then solve the problems
5. Final Exam & Review
HOMEWORK:
1. Final Exam Review will be posted tonight. Check it out.
2. Notes Sheet for final exam - due 05/27
3. You final exam will have two parts if you're a Junior, and one part (written only) if you're a senior (yippie!)
A. Written Portion. In Class on Wednesday 05/27
B. Lab Practical. In Class during finals period 06/01 (juniors only)