DAY 154

GOALS: swbat...

1. Explore non-mechanical waves (Electro-Magnetic Waves)

2. pass the quiz

CLASSWORK:

1. 153C: Introduction to Non-Mechanical Waves (Electromagnetic Waves)

It's time to transition from something we can see (mechanical waves) to something we can only see the effect of (electromagnetic waves). We'll start off with some reading to build your vocabulary, and your conceptual knowledge.

1. The guided reading handout in on Schoology. Should you be unable to access Schoology, please let me know so I can help you gain access, and in the interim use this link: LINK

2. The reading is from a copy of a conceptual physics book, available here: LINK

2. 154A: Quiz 8: Wave Interactions & Sound

Goals: SWBAT...

1. pass the quiz with a score of 80% or higher

2. describe patterns of constructive and destructive interference

3. properly create a setup to measure the width of human hair

4. measure the laser light fringe, and calculate the width of your hair

154A: Color/Light Quiz (Kiosk App for Schoology)

WARM-UP

1. How wide is one piece of your hair? To answer, estimate how many of your hairs stacked side-by-side would be equivalent to the width of this 1mm wide line ---> | Next divide 1mm/# of hairs. That's your estimate.

3. What is constructive interference?

4. What is destructive interference?

5. Copy the image from the board - how many wave patterns would be created by the object blocking the light source?

CLASSWORK

1. 154: If you need it, here's a review of Refraction from Day 153 (VIDEO)

2. 154B: "How wide is your hair?" Lab

LINK Read (skip #11). Also note that to save time, steps 1-4 will be different, as we will be mounting the hair directly to the front of the laser.

- Materials: Ruler, strand of hair, tape, piece of paper, laser

Discuss safety:

List three safety concerns:
To collect data, you'll need the laser on for an extended period of time. Should you tape the power button on? Why/Why not?
Lasers are fragile. Describe how you can handle them to keep them functioning.
- Practice time:
  - For successful data collection, you'll need to...
    - ...mount the hair to the front of the laser.
    - ...move your table or chair so that the distance between the hair and the target (paper on the wall) is less than or equal to one meter.
- Data Analysis.
  - You'll be measuring the initial (close) and final (far) sides of each fringe. Why not just measure the middle of the fringe?
    - How do we find the average distance of each fringe from the central point?
    - Collect data in the data table (provided on Schoology), and use the formula provided to find the width of the hair.
- Lab is Due Sunday 11:59pm via Schoology.

LEARNING AT HOME (HW)

- Tomorrow we begin our final unit on Electricity and Magnetism. We'll start with electrostatics (think: static electricity)

- Your Homework is Guided Reading 154C. The document is on Schoology, and the textbook reading is here (LINK). Due by 11:59pm tonight.

Can't access the lab document for 154B? Here's a link: LINK

Here’s the link to the guided reading: https://docs.google.com/document/d/1fFt1nabvAVbWAPMY5lc5jWNnQSy3tvwqhu4taxP3H8I