Presentation on theme: "2 days (max) Day 1 Day 2. Good Vibrations Monday March 26 th, 2012 Warm-up: (1) Draw a tuning fork on your paper. (2) Using prior knowledge, describe."— Presentation transcript:
Good Vibrations Monday March 26 th, 2012 Warm-up: (1) Draw a tuning fork on your paper. (2) Using prior knowledge, describe what a tuning fork does. Objective: Students will be able to analyze the behavior of sound waves in order to explain how sound waves transfer energy. Homework:
Good Vibrations INBOX From Date: Today We have been learning a lot about waves in general. Im interested in the sound job. Do you think what we learned about waves and energy applies to sound? It would be logical but sometimes the logical isnt always correct. I think I should check into this to be safe. Maybe I can conduct some investigations to see. Gotta split! I have a lot to research.
Activity A: Observing Energy Transfer The world is full of many different sounds. The roar of a jetliner, the crash of a ball through a window, the voice of a singer; these and other sounds result from energy transfers. In this investigation, you will observe energy transfers which produce sound. FIGURE 1 Tines Handle
Hold the tuning fork in one hand. Strike the tuning fork with the mallet. See Figure 1. 1. Describe your observations of the tuning fork tines after being struck by the mallet.
2.Strike the tuning fork. Touch the tines to the surface of the water in the beaker. What evidence is there that energy from the tuning fork was transferred to the water? The water splashed around at the surface of the beaker. This shows that the energy transferred from the tuning fork to the water.
Review/ Discussion Identify the source of energy that caused the vibrations on the tuning fork. Striking the tuning fork (creating a disturbance) transferred the energy into the tuning fork. We call the motion of the tuning fork tines vibration. A vibration is a rapid back-and-forth repeating motion.
3. Complete the sequence chain to show the energy transfers in procedure 2. Striking the tuning fork Tuning Fork Water
Strike the tuning fork. Place the tuning fork near, but not touching, your ear. 4. Strike the tuning fork. Place the tuning fork near, but not touching, your ear. Identify evidence that energy in the tuning fork is transferred to the air. 5. Strike the tuning fork against the desk. Pick up a piece of paper and touch the tines to the paper. Identify evidence that energy in the tuning fork is transferred to the paper. 6. Strike the tuning fork. Place the bottom of the tuning fork on the table top. Identify evidence that energy in the tuning fork is transferred to the table.
Analysis #1 The strings of the banjo make sounds that are similar to the tone produced by the tuning fork. Construct a sequence chain to show the energy transfers that occur when the banjo is played and you hear the sound.
Good Vibrations Tuesday March 27 th, 2012 Warm-up: (1) Identify 2 pieces of evidence that a tuning fork has energy in it after striking a table. Objective: Students will be able to analyze the behavior of sound waves in order to explain how sound waves transfer energy. Homework: Wave Interactions HW #2
Classwork You have observed evidence of energy transfer in sound waves. How exactly are sound waves produced? How is energy transferred in a sound wave? In order to answer these questions, you will need to do a little research. Read the passage The Nature of Sound on pages 36-37 of the Prentice Hall: Science Explorer, Sound and Light. 1. Explain how sounds are produced. Justify your answer using information from the text. 2. Explain how energy is transferred in a sound wave. Justify your response using information from the reading.
1. Explain how sounds are produced. Justify your answer using information from the text. Sounds are made when the medium is vibrating. For example, a drum creates a disturbance which pushes the molecules of the air near it and creates sound.
2. Explain how energy is transferred in a sound wave. Justify your response using information from the reading. Energy is transferred in a sound wave by the creation of compressions and rarefactions, which will cause the molecules of the medium to hit other molecules. This passes the energy along.
Vocabulary Reference Compressions When the particles of a medium are close together Rarefactions When the particles of a medium are far apart
Exit Ticket An opera singer is practicing for a performance. When she hits a high note, the glass of water on the table shakes. Explain why the glass shakes. Justify your answer using what you have learned about energy transfer.
Demonstration Observe the demonstration. Determine how energy is related to loudness of a sound. As the energy put into making the sound __________, the loudness of the sound _________________.
Prediction Predict what you think will happen to the loudness of the sound provided by the ruler as we increase the amplitude. As we increase the amplitude of the ruler I think the loudness will…..
Investigation Observe the loudness of the ruler for each amplitude. Determine if the loudness was loud or soft. AMPLITUDE (cm)LOUDNESS (relative) 1 cm Soft Loud 10 cm Soft Loud
Conclusion As the amplitude _______ _____ the loudness of a sound __________. This is known as a _______________ relationship.