DAY 149
Video Lecture part 1: https://youtu.be/jgaIOcgSD-I <--- watch and see my kids "help" by not cooperating. Yay work from home.
Video Lecture part 2: https://youtu.be/dX5MFgfjOjM <---THIS IS SUPER COOL. And if you like ASMR, bonus points...
Mr. Alexander
WARM-UP
1. The speed of sound in solid iron is 5,120 m/s. How long would it take a sound wave to travel through 40,075,000 m of iron?
2. Could a sound wave travel that far?
CLASSWORK
1. Questions on our Changing Pitch Lab. Send me a Remind or email/schoology message
2. 149A:
Lab Activity – Tuning Forks and Waves
Purpose – make observation about the waves formed by a tuning fork
You will complete this activity on Schoology. Due Thursday.
Pre-lab Question
The speed of sound in room temperature air is approximately 343 m/s. Calculate the wavelength of a sound wave that has a frequency of 500 Hz.
Instructions, Observations, and Calculations
You will need two tuning forks (one high and one low), a binder (or short stack of paper to strike the tuning fork on) and a cup with water to complete the observations.
write down the two frequencies of your tuning forks. They can be found stamped on the fork.
Strike each tuning fork on the paper. Compare the sounds that the tuning forks make and write one observation.
Observe the tuning fork vibrations with your eyes. Write one observation about what you see.
Strike the tuning fork and have it touch your ear and nose. Write one observation about what you feel.
Strike a tuning fork and place it in a cup of water. Write one observation about what you see.
Calculate the wavelength of the tuning fork using the speed of sound given in Pre-Lab question #1 and the frequency on the tuning forks.
Conclusion Questions
Why does sound travel faster when the air is warmer than when it's colder? Think: how could you use the concept of how particles interact in longitudinal sound wave to help explain your answer. Feel free to use the internet to help find your answer
Which tuning fork has a higher pitch? How do you know?
Which turning fork (long or short) has a lower frequency? What about that forks shape forces it to have a lower frequency?
Compare and contrast the low frequency and high frequency tuning forks using a Venn Diagram
How could you increase the intensity of the sound waves you produced using tuning forks?
ECHO PRACTICE: Bats can use echo location to navigate and find prey. If a bat emits a sound then hears it 0.02 seconds later, how far away is the object?
ESSENTIAL QUESTION: What are the characteristics of EM waves?
GOALS: swbat...
1. observe that light can only be seen when it bounces off an object
2. describe which filters transmit certain colors, and which absorb colors
3. see that two filters can combine to affect the color of transmitted light
WARM-UP (4 minutes)
:-) be an independent learner!
Looking forward to hearing about all the good stuff you've learned, and to seeing you all next Monday,
Mr. Alexander
1. Natural philosophers have long pondered the underlying reasons for color in nature. One common historical belief was that colored objects in nature produce small particles (perhaps light particles) that subsequently reach our eyes. Different objects produce different colored particles, thus contributing to their different appearance. Is this belief accurate or not? _____________ Justify your answer.
2. What color does a red shirt appear when the room lights are turned off and the room is entirely dark? ____________ What about a blue shirt? ____________ ... a green shirt? ____________
CLASSWORK
1. 149A: Colors: How Do They Interact?
- Please read the instructions on the Color Vision Simulation
- read handout, answer questions, and solve problems.
- again, the assignment is on SCHOOLOGY. Go there for the assignment.
HOMEWORK
If you didn't complete today's classwork, complete it by 11:59pm tonight, and submit it via Schoology. It will be late, and you will lose some credit, however partial credit is better than no credit.
Unable to access today's CW assignment? Here's the LINK