1. WAVE DRAWING HOMEWORK DEBRIEF Tahoma Jr. High 8 th Grade Science Maple Valley, WA

2. ___________1. Which letters are the crests? a. A, D b. E, Ic. H, J d. B, G e. F, H

3. ___________2. Which letters are the troughs? a. A, D b. E, I c. H, J d. B, G e. F, H

4. ___________3. Which letters are the rest points? a. A, D, F, H, J b. E, I c. A, C, D, F, H, J d. B, G Answer “c.” is OK, but Rest Points should be on the wave line, so answer “a.” is a better one.

5. ___________4. Which distance is the amplitude? a. B ‑ C b. A ‑ D c. E ‑ G d. E ‑ I e. A ‑ J

6. ___________5. Which distance is exactly 1 wavelength? a. A ‑ J b. A ‑ Dc. D ‑ F d. B ‑ G e. D ‑ J

7. ___________6. How many units equal one wavelength? a. 2 b. 4 c. 6 d. 8 e. 10

8. 7. Between points X and Y on Figure 3 draw a wave that has a wavelength of 4 units and an amplitude of 5 units.

9. A. Draw a wave with wavelength of 4 and amplitude of 3.

10. B. Draw a wave with wavelength of 8 and amplitude of 4.

11. Which wave has the highest frequency? A or B? _____ If these waves represented sound, which one would have the highest pitch? A or B?_____ Which one would be the loudest? A or B? ______ A A B

12. Draw both waves on the same graph below and label A and B. A B Circle areas on the graph where Constructive Interference happens (label as “C.I.”) C.I. D.I. C.I. D.I. Circle areas on the graph where Destructive Interference happens (label as “D.I.”)

13. A B Constructive Interference is where similar waves get added together and make the energy (volume) “louder”. Destructive Interference is where opposite waves cancel each other out and energy (volume) is “quieter”. (this is what noise cancelling headphones do) LOUDEST QUIETEST see next slide

14. show TBBT video clip – Sheldon in Theater finding just the right seat now 2 mins END SHOW