1. Physics Chapter 5 Section 3 Sounds in strings revisited

2. Mar 2 nd, 2012 HW: 5.3 PTG, p 517 #1-5, Due Tuesday  Learning Objective  Explain direct and inverse relationships  Explain how wave speed, wavelength, and frequency are related  Create a data table to organize data for experiments.  Success Criteria  Describe what determines wavelength and sound  Describe the relationship between tension and speed of a wave  Describe the relationship between wavelength and frequency  Determine the velocity of a wave using the equation  Calculate wavelength of a standing wave  Describe how the pitch of the sound produced by a vibrating string depends on the wave speed, wavelength and frequency of the waves on the string.  Do Now:  Finish Vocab Boxes  5.2 Quiz  Write LO and SC on new left page  WDYS/WDYT on page 508  Agenda  Do Now  Investigation 5.3  Summary/Exit Ticket

3. Mar 2 nd, 2012 HW: 5.3 PTG, p 517 #1-5, Due Wed.  Learning Objective  Explain direct and inverse relationships  Explain how wave speed, wavelength, and frequency are related  Create a data table to organize data for experiments.  Success Criteria  Describe what determines wavelength and sound  Describe the relationship between tension and speed of a wave  Describe the relationship between wavelength and frequency  Determine the velocity of a wave using the equation  Calculate wavelength of a standing wave  Describe how the pitch of the sound produced by a vibrating string depends on the wave speed, wavelength and frequency of the waves on the string.  Do Now:  Finish data table and notebook layout for 5.3 #1- 7  Agenda  Do Now  Investigation 5.3  Summary/Exit Ticket

4. Investigate  Read procedures 1-7  Lay out notebook and create data table for #4-6  Make spaces to answer questions 7-8

5. Sample Data Table String LengthWavelength (2x string length) Pitch (high, low, or medium)

6. Investigate 5.3 (Guidelines for 1-7)  Same set-up as Investigation 1  What kind of wave is the string making?  How do you calculate wavelength?  Standing Wave - this is similar to the waves made in the spring  The wavelength is twice the length of the string

7. Investigation 5.3 (Guidelines for 8-12)  Complete with your group  Remember that speed is distance traveled over a period of time.

8. Summary/Exit Ticket  How does changing the wavelength effect the velocity?  How does changing the frequency effect the velocity?

9. Mar 3 rd, 2012 HW: 5.3 PTG, p 517 #1-5, Due Wednesday Sign up for Honors Meetings!  Learning Objective  Explain direct and inverse relationships  Explain how wave speed, wavelength, and frequency are related  Create a data table to organize data for experiments.  Success Criteria  Describe what determines wavelength and sound  Describe the relationship between tension and speed of a wave  Describe the relationship between wavelength and frequency  Determine the velocity of a wave using the equation  Calculate wavelength of a standing wave  Describe how the pitch of the sound produced by a vibrating string depends on the wave speed, wavelength and frequency of the waves on the string.  Do Now:  If you keep the wavelength the same, how can you change the velocity of the wave?  Agenda  Do Now  Notes 5.3  Summary/Exit Ticket

10. Physics Talk 5.3  What kind of wave does the vibrating string produce?  How do you calculate the wavelength?  A standing wave  The wavelength is twice the length of the string

11. Physics Talk 5.3  How does frequency relate to pitch?  Equation for wave speed  The higher the frequency, the higher the pitch  Wave speed = wave frequency x wavelength

12. Physics Talk 5.3  How do we solve for frequency?  Rearrange the equation to read

13. Physics Talk 5.3  What happened when you shortened the length of the string?  How is this shown in the equation?  The wavelength was shortened  Pitch increased  Frequency increased  Dividing by a smaller number on the bottom, gives us a larger frequency  If you have to share something with fewer people, you get more

14.  http://www.youtu be.com/watch?v= HpovwbPGEoo http://www.youtu be.com/watch?v= HpovwbPGEoo  http://www.youtu be.com/watch?v= LDekBnEqTUk&fea ture=related http://www.youtu be.com/watch?v= LDekBnEqTUk&fea ture=related  http://www.youtu be.com/watch?v= n- D3tsZIoZ8&featur e=related http://www.youtu be.com/watch?v= n- D3tsZIoZ8&featur e=related  http://www.youtu be.com/watch?v= YAh4- 4UPr64&feature=r elated http://www.youtu be.com/watch?v= YAh4- 4UPr64&feature=r elated

15. Physics Talk 5.3  What kind of mathematical relationship does this show?  What is an inverse relationship?  Inverse Relationship  A relationship where when one value increases, the other decreases, or as one value decreases, the other increases

16. Physics Talk 5.3  How is frequency an example of an inverse relationship?  Decreasing the wavelength increases the frequency

17. Physics Talk 5.3  How are tension and pitch related?  Since the wavelength did not change, and the frequency increased, this means the wave speed increased  An increase in tension, produces a larger force, which leads to a larger acceleration on the string (F=ma)

18. Physics Talk 5.3  How are tension and pitch related? (continued)  When the force accelerates the string, the wave speed increases and the string vibrates faster  Since the wave is faster, the frequency must also be faster, leading to a higher pitch

19. Physics Talk 5.3  What is a direct relationship?  Example of direct relationship  A relationship where as one value increases, the other value also increases  Increasing the wave speed also increases the frequency and pitch

20. Physics Talk 5.3  How does increasing the thickness of the string lead to a different pitch?  When the string is larger, it has a greater mass for the wave to travel through  This also means it takes more force to stop the string from vibrating  The force is the tension in the string

21. Physics Talk 5.3  How does increasing the thickness of the string lead to a different pitch?  Since the mass is heavier, the acceleration will be less (F=ma)  This creates a slower wave speed  Decreasing wave speed will decrease the frequency and pitch

22. Physics Talk 5.3  When do standing waves occur?  How does string length related to standing waves?  When the length of the coiled spring or string has a certain relationship  The length much be 1/2, 1, 3/2, 2, etc of the wavelength

23. Physics Talk 5.3  Equation for standing waves  Standing waves occur when the following equation is met: L = string length n = the number of antinodes (crests) Lambda = wavelength

24. Physics Talk 5.3  How do you calculate the period for a wave?  How is a period related to the frequency?  T is the period  The frequency is the reciprocal of the period

25. Sample Problems 1 and 2  p 513  Use GUTS  When in doubt, draw it out  Pictures are very helpful!

26. LO and SC reflection  Learning Objective  Explain direct and inverse relationships  Explain how wave speed, wavelength, and frequency are related  Create a data table to organize data for experiments.  Success Criteria  Describe what determines wavelength and sound  Describe the relationship between tension and speed of a wave  Describe the relationship between wavelength and frequency  Determine the velocity of a wave using the equation  Calculate wavelength of a standing wave  Describe how the pitch of the sound produced by a vibrating string depends on the wave speed, wavelength and frequency of the waves on the string.

27. January 19, 2011 Sign up for Honors Meetings!  Learning Objective  Explain direct and inverse relationships  Explain how wave speed, wavelength, and frequency are related  Create a data table to organize data for experiments.  Success Criteria  Describe what determines wavelength and sound  Describe the relationship between tension and speed of a wave  Describe the relationship between wavelength and frequency  Determine the velocity of a wave using the equation  Calculate wavelength of a standing wave  Describe how the pitch of the sound produced by a vibrating string depends on the wave speed, wavelength and frequency of the waves on the string.  Do Now:  Finish LO and SC Reflections  Essential Questions, pg. 516  What does it mean?  How do you know?  Why should you care?  Agenda  Do Now  Summary  Quiz

28. Essential Questions-pg. 516  What does it mean?  How do you know?  Why should you care?