Unit 9: Let Us Entertain You

Essential Questions  What are the relationships among wavelength, frequency, and speed of a wave?  How are vibrations and pitch varied in a string to produce different sounds?  How does vibrating air produce sound?  How do plane and curved mirrors affect the image that is produced?  How can the colour of an object appear to be different by shining different colour light on it?

Chapter Challenge  You will work with your partner to create a 2-4 minute light and sound show  This can be performed “live” or shown as a video  Along with it, there will be a written report that explains the physics concepts used in the show and explains why each concept is important  The sound must come from instruments or noise makers you make yourself  Due date: Monday, June 3 (During exam time)

Day 1: Making Waves  Learning Objectives:  Observe the motion of a pulse  Measure the speed of a wave  Observe standing waves  Investigate the relationship among wave speed, wavelength, and frequency  Make a model of wave motion

Starter  Tsunamis are giant ocean waves caused by an underwater earthquake  Waves can reach extremely high heights, for example in Thailand (2004), the waves reached 30m  How does water move to make a wave?  How does a wave travel?  Time: 10 minutes

Video: Japan Earthquake

Activity 1  Draw a picture of a wave that includes the following terms:  Amplitude  Wavelength  Crest  Trough  Time: 15 minutes

Activity 2  For you to do, pg. 327  Steps #1-10  Write down observations, record data  Data table will be provided for you  Make a concluding statement about the relationship of frequency, wavelength and speed of a wave  Time: 45 minutes

Activity 3  Discussion of results and conclusion  Draw a picture that shows what happens to the frequency of a wave if you increase or decrease the wavelength  Time: 10 minutes

Homework  For you to read, pg. 331  Physics talk, pg. 333  Physics to go, pg. 337 #1, 7, 10, 11, 12

Day 2: Sounds in Strings  Learning Objectives:  Observe the effect of string length and tension upon pitch produced  Control the variables of tension and length  Summarize experimental results  Calculate wavelength of a standing wave  Organize data in a table

Starter  When the ancient Greeks made stringed musical instruments, they discovered that cutting the length of the string by half or two-thirds produced other pleasing sounds.  How do guitarists or violinists today make different sounds?  Time: 10 minutes

Video: The Physics of Sound

Activity 1  For you to do, pg. 340 in lab groups  Steps #1-7  Record the data table and answer the questions/observations to go along with the steps  Hand in 1/lab group at the end of the period  All equipment is on back table  Time: 45 minutes

Activity 2  Physics to go, pg. 344 #7  There are wood blocks in the back storage area that have strings on them  Work with your lab group to produce different sounds and answer the following:  Explain how different sounds are being produced using wavelength, frequency, pitch, and standing waves in your explanation  Describe how the instrument works using wavelength, frequency, and standing waves in your description  Hand in with the “for you to do” activity  Time: 20 minutes

Homework  Please take your roller coaster models home  For you to read, pg. 343  Physics to go, pg. 344 #1, 2, 3

Day 3: Sounds from Vibrating Air  Learning Objective:  Identify resonance in different kinds of tubes  Observe how resonance pitch changes with length of tube  Observe the effect of closing one end of the tube  Summarize experimental results  Relate pitch observations to drawings of standing waves  Organize observations to find a pattern

Starter  The longest organ pipes are about 11m long. A flute, is about 0.5m long and makes musical sound in the same way.  How do a flute an organ pipes make sound?  Time: 15 minutes

Video: Sound in pipes

Video: Fresh Prince  Season 1, Episode 1  Time: 13:51

Activity 1  For you to do, pg. 347 Steps 1-3  Data table is provided for you  Write a concluding statement about straw length and the pitch obtained  Time: 20 minutes

Activity 2  For you to do, pg. 347, steps 4-5  Write a concluding statement about the amount of water in the test tube and the sound you hear.  How can this be changed to use in your sound and light show? (i.e. what materials could you use?)  Time: 20 minutes

Activity 3  Create an “instrument” that uses at least one of the principles that we have discussed thus far  Wavelength  Frequency  Pitch  Create an advertisement that tries to sell your instrument to the rest of the class  Time: 30 minutes

Homework  Physics Talk, pg. 348  For you to read, pg. 349  Physics to go, pg. 351 #1, 2, 3, 4

Day 4: Reflected Light (60 min)  Learning Objectives:  Identify the normal of a mirror  Measure angles of incidence and reflection  Observe the relationship between the angle of incidence and the angle of reflection  Observe changes in the reflections of letters  Identify patterns in multiple reflections

Day 5: Curved Mirrors  Learning Objectives:  Identify the focus and focal length of a curved mirror  Observe virtual images in a convex mirror  Observe real and virtual images in a concave mirror  Measure and graph image distance vs. object distance for a convex mirror  Summarize observations in a sentence

Day 6: Refraction of Light  Learning Objectives:

Day 7: Colour