DAY 131
Videos will be embedded below by 12 noon. (Making videos takes a long time!)
Essential Question: How can energy be transferred?
GOALS: SWBAT...
1. Calculate MA
2. Calculate IMA of a bicycle
3. Solve problems using MA and IMA
WARM-UP 130 (5min)
1. Classify the tools listed below as a lever, wheel and axle, inclined plane, wedge, or pulley. Look up the tools on the web if you aren't sure what they look like or how they work.
a. screwdriver
b. pliers
c. chisel
d. nail puller (link HERE scroll down to the first picture (it looks like a crowbar)
Warm Up Review
VIDEO LINK
a. wheel and axle (see pic below)
b. two levers
c. wedge
d. lever
CLASSWORK
1. Review Day 130 (5 min)
Video LINK
2. 131A: Mechanical Advantage Reading and Problem Solving Example (20 min)
Read pages 269-270 (LINK). While reading, pay super close attention to the relationship (ratio) between the parts of a bicycle used to do calculations. Video LINK
Watch this video prior to starting question 33: Video LINK
Answer question 33 on page 273 (Reading LINK)
Watch this after question 33. Revise your answer if necessary (video LINK)
Copy Example Problem #4 from page 271 into your notes (notebook check this Thursday via Schoology - hope you've been keeping up!).
Sketch the image, and write your givens (aka known) and unknown.
Solve the problem, checking your work with the textbook example when you get stuck.
Should IMA be small for a bike? Read the "Evaluate your Answer" at the bottom of the page and find out!
3. 131B: Applying Mechanical Advantage Concepts to Problem Solving (10 min)
a. Pg 272 answer the following questions. For each question, you may skip the questions about efficiency. We'll cover that tomorrow.
24.
25. skip c
26. skip b
4. 131C: EXIT QUESTIONS (4 min)
1. Write a sentence explaining how to calculate IMA
2. Is the goal of a bike to be a machine which multiplies force or distance?
3. Why is the IMA of a bicycle less than 1?
Answers to 131B
https://drive.google.com/open?id=1imTewCbSLfXv70kHxgV6Vdf3y1P6kfa7
Answers to 131C
1. Divide the effort displacement by the resistance displacement (displacement of the load)
2. Multiply distance
3. Because the point of a bicycle is to trade a reduction in force for an increase in distance.
2. Use the concept of mechanical advantage to explain how gears on a bicycle make pedaling easier.
Essential Questions:What is a wave?
Goals: SWBAT...
1. Discuss waves’ properties using common vocabulary and they will be able to predict the behavior of waves
2. Describe how changing one characteristic of a wave affect the other characteristics.
Warm-Up (5min):
1. Right now you're hearing sounds (sound waves). Through what medium are those sound waves travelling?
2. Draw a transverse wave and a longitudinal wave.
3. What's an easy way to memorize the direction a longitudinal wave moves?
Waves on a String: https://phet.colorado.edu/en/simulation/wave-on-a-string
CLASSWORK
1. 131A: Summative Lab
This is a review of most of the material we've covered this week. My hope is that by the end of the period, this all makes 100% clear, perfect sense to you.
Make a copy of the lab, share it with me at josh.alexander@lausd.net, and complete the lab in class today. It's a short assignment. Write-up due Monday 11:59pm.
LINK: https://docs.google.com/document/d/1NCO6GM_vdhffqaEib0IcWPstnr4fIQMZEA3DjaAaCe4/edit?usp=sharing
3. 131B: Oral Quiz
I'll call you up one by one.
At Home Learning (HW)
1. Complete lab
2. 131C: Waves Extra credit. Need to replace a missing HW grade? Complete the crossword puzzle (don't do the math problems - just the crossword). Due Monday.
LINK: https://drive.google.com/file/d/0B-AiPYEb3nFVT21US202cVFQbXM/view