1. TCAP Practice Questions Complete question #1-4 Please do NOT write in TCAP booklet! Bubble in the correct answer on the bubble sheet provided. Scan your bubble sheet and record your score. We will discuss the questions after everyone has scanned. You have 5 minutes to answer the questions. Your time starts as soon as the bell rings. BELLWORK 4/7/14

2. THINK OF A TIME YOU HAVE EXPERIENCED WAVES… 70. Waves

3. Objectives SPI 0707.11.5 Compare and contrast the different parts of a wave. SPI 0707.11.6 Differentiate between transverse and longitudinal waves in terms of how the are produced and transmitted.

4. NATURE OF WAVES: A wave is a disturbance that transmits energy through empty space or through a medium. Look @ pg. 602!

5. The “Medium” of a Wave… A medium is the substance or material the wave travels through –Can be a SOLID, LIQUID, or GAS –Example: Seismic waves (earthquakes) travel through the ground Ocean waves travel through water Light waves travel through space from the sun

6. Question: You are a commander of a space station located about halfway between Earth and the moon. You are in the Command Center, and your chief of security tells you that sensors have just detected an explosion 61.054 km from the station. How long will it be before you hear the sound of the explosion? Sound waves need a medium through which to travel. If there are no particles to vibrate, no sound is possible! Electromagnetic waves, like visible light, can transfer energy without going through a medium.

7. Longitudinal vs. Transverse Waves

8. Transverse Waves Examples: light waves, water waves electromagnetic waves

9. Electromagnetic Waves ROY G. BIV was a colorful guy.

10. Parts of Transverse Waves Crest – highest point (above) Trough – lowest point (below)

11. Transverse Particle Motion Particles or energy moves perpendicular to wave motion Draw a transverse wave. Label the wave motion, particle motion, crest, & trough.

12. Check for Understanding…

13. Longitudinal Waves Examples: sound waves

14. Parts of Longitudinal Waves: Compression: place where particles are closest together Rarefaction: place where particles are furthest apart

15. Longitudinal Particle Motion Particles or energy moves parallel to wave motion Draw a longitudinal wave. Label the wave motion, particle motion, compression, & rarefaction.

16. Check for Understanding… A wave is transporting energy from left to right. The particles of the medium are moving back and forth in a leftward and rightward direction. This type of wave is known as a ____. a. mechanical b. electromagnetic c. transverse d. longitudinal

17. Check out this longitudinal wave… http://utahscience.oremjr.alpine.k12.ut.us/sci ber08/8th/forces/movies/compress.mov

18. Properties of Waves Amplitude – height of the wave above or below rest Larger amplitude = more energy Label the amplitude on the transverse wave.

19. Describe the amplitude…

20. Wavelength= distance between any two corresponding locations. Usually measured in one of three ways: 1.crest to next crest 2.trough to next trough 3.from the start of a wave cycle to the next starting point Label the wavelength on both types of waves.

21. Check for Understanding… As a wavelength decreases, the crests of the wave A become wider. B become shorter. C get closer together. D get farther apart.

22. Frequency: The number of waves in given amount of time higher frequency = more energy Units: Hz = Hertz

23. Frequency: Measure the frequency by counting either the number of crests or troughs that pass a point in a certain amount of time.

24. Count the frequency for each wave. High or Low Frequency?

25. Properties of Waves Wave speed is the speed at which a wave travels. Wave speed can be calculated by using the following formula: v = λ x f or v = λ f v = wave speed λ = wavelength f = frequency Determine the wave speed of a wave that has a wavelength of 5 m and a frequency of 4 Hz. Express the units as m/s.

26. Longitudinal vs. Transverse Waves

27. Let’s make waves…

28. Wave Displacement (motion of the particles)

29. Surface Waves

30. Check for Understanding

31. How does the pencil look broken?

32. Wave Interactions The frequencies at which standing waves are made are called resonant frequencies. When an object vibrating at or near the resonant frequency of a second object causes the second object to vibrate, resonance occurs. A resonating object absorbs energy from the vibrating object and vibrates, too. Tacoma Narrows Bridge AKA “Galloping Gertie” is a phenomenon, or an extraordinary event, that caused a lot of destruction because of resonance. Watch this Video!

33. 71. Waves Lab Create a transverse and longitudinal wave using paper confetti.