Yesterday's assignment was a bit heavy, so I made today's deliberately light. Today should take about 15 minutes. For your notebook check, I'm only checking four (4) days, and those are Day 129 - Day 132. Please upload a pdf to schoology, instructions for how to do that are below.
Warm-Up
1. Define "efficiency"
2. What does it mean for a car to be efficient?
Classwork
1. 132A: Efficiency
- Read page 268 on efficiency (reading LINK)
- Answer question 32 on page 273
2. 132B: Efficiency Problem Solving
Pg 272 answer 25c
Video here with a lesson for these topics LINK
3. 132C: Notebook Check
Day 129-132 only. Please upload a .pdf Here's how to do that. Instructions LINK
Notebook check is due by Friday, 11:59pm, so if you need extra time, you have it.
GOALS: SWBAT...
1. Memorize symbols for wave frequency, period, and wavelength
2. Recognize that wavelength is inversely proportional to frequency
3. Solve math problems to find wave speed, wavelength, and frequency
WARM-UP 132
1. TRUE or FALSE: In order for Xochitl to hear Sharkeisha , air molecules must move from the lips of Sharkeisha to the ears of Xochitl.
2. How does the sound move from Sharkeisha to Xochitl?
CLASSWORK
1. #132A: Wave Speed and Frequency: Notes & Problem Solving
Today we'll practice relating frequency and wavelength. You should notice that they are (directly/inversely(?)) proportional.
Wave demo - .5 waves ---> 1.5 waves
Example:
#1
What are the symbols for frequency, period, speed, and wavelength?
How can we connect the speed equation we already know (speed=distance/time) to waves?
The problem ends with a unit of 1/s. One what over seconds? Or...one what per second?
Solve each of the following using GUESS. Page 2, #1-8
https://drive.google.com/file/d/0B-AiPYEb3nFVT21US202cVFQbXM/view
HINTS:
#2 & #5: consider 17-19 from last weeks Guided Reading
17. A complete back and forth vibration is one cycle. If it occurs in one second, the frequency is one vibration per second or one cycle per second.
18. The unit of frequency is called the hertz (Hz). A frequency of one cycle per second is 1 hertz, two cycles per second is 2 hertz, and so on.
19. Higher frequencies are measured in kilohertz (kHz– thousands of hertz), and still higher frequencies in megahertz (MHz– millions of hertz) or gigahertz (GHz– billions of hertz).
#3: Why is the mention of "echo" important?
2. #132B: Waves: Check Your Understanding
Answer the four questions below. Use last week's Homework reading to assist (link is here --> LINK).
1. Curly and Moe are conducting a wave experiment using a slinky. Curly introduces a disturbance into the slinky by giving it a quick back and forth jerk. Moe places his cheek (facial) at the opposite end of the slinky. Using the terminology of this unit, describe what Moe experiences as the pulse reaches the other end of the slinky.
2. Mac and Tosh are experimenting with pulses on a rope. They vibrate an end up and down to create the pulse and observe it moving from end to end. How does the position of a point on the rope, before the pulse comes, compare to the position after the pulse has passed?
3. Minute after minute, hour after hour, day after day, ocean waves continue to splash onto the shore. Explain why the beach is not completely submerged and why the middle of the ocean has not yet been depleted of its water supply.
4. A medium is able to transport a wave from one location to another because the particles of the medium are ____.
a. frictionless
b. isolated from one another
c. able to interact
d. very light
Homework
1. Complete any incomplete CW from today. Answers are below. You're still responsible for using GUESS, and showing all your work.
1. 2.9 waves/s
2. 0.7 m
3. a. 1500 m b. 770 m
4. 4 m/s
5. 0.04 m
6. T = 13 s f = 0.077 waves/second
7. 2 x 1020 waves/second
8. 0.03 waves/second
2. Wave on a String Phet Lab is due electronically via Google Doc share tonight 11:59pm
3. 133A: Basic Waves (Slinky) Lab
Read ahead, as we'll be learning via this lab Tuesday
LINK