1. Challenge/Connection Exemplar Answers

2. Challenge Question Explain why you can’t cause a floating leaf to move to the edge of a pond by throwing rocks behind it? Waves carry only energy not matter. A leaf is matter.

3. Connection Stadium Waves! –What kind are they? Mechanical –What type are they? Transverse –How do you know? They are mechanical because they require a medium (the people). It is transverse because the people move up and down but the energy goes left to right.

4. Challenge Question You are listening to your favorite CD and your mom calls out and asks you to “TURN THAT MUSIC DOWN”. Which of the 3 physical properties of waves is she asking you to change? Explain. Amplitude – the larger the amplitude the louder the sound. So she is asking you to lower the amplitude.

5. Connection Reread the top of page 516, complete the chart with the following words: largesmallhigh low Wave Property Speed Boat Waves Waves from Breeze Amplitudelargesmall Frequencylowhigh

6. Challenge Question What would happen if light waves could be diffracted as much as sound waves? Sound Waves Light Waves? You could see the radio around the corner.

7. Connection A monster or rogue wave is generally described as a wave that is twice the height of the surrounding waves. Describe what would make such a wave possible. The crest of two waves would meet causing their amplitudes to add together. It is called constructive interference.

8. Challenge ? If a tree falls in a forest and no one is around to hear it, does it make a sound? Yes, the tree would hit the ground and cause vibrations. The vibrations would cause sound although no one would be around to hear it.

9. Connection A meteor hits a space stations orbiting high above the Earth. –Do astronauts inside the station hear the impact? Explain. –Does an astronaut working outside the space station near hear the impact? Explain. Yes – the matter of the ship and air inside would be the medium to transfer the vibrations to the astronauts ears. No – space is a vacuum. A vacuum has no matter to transfer the vibrations to the astronaut.

10. Challenge? Describe how the Doppler effect helps a dolphins determine whether a fish is moving away from it or toward it? The Doppler effect is the apparent change of frequency if either the source of wave is moving toward or away from the observer, or the observer is moving toward or away from the source. The dolphin sends out a sound pulse and listens to the frequency of the echo. If the echo has a higher frequency than the original sound the fish is moving closer, if the frequency is lower the fish is moving away.

11. Connection Why is the buzz of a bumble bee lower than the hum of a mosquito? Why is the buzz of the bumble be louder than the hum of the mosquito? Bee’s wings beat slower. slower frequency means Lower pitch Bee’s wings are bigger, They move farther away from their resting position which means they have larger amplitude. Large Amplitude means loud sound

12. Challenge ? Sometimes people who play in bands line their practice rooms with egg trays. Explain why might they do this. Softer materials absorb sound and bumpy materials disrupt the echos.

13. Connection Why can you hear the bass notes of a song throughout the whole house but usually not the lyrics? Because bass has longer wavelengths. Longer wavelengths diffract more around barriers transfer the bass to other parts of the house.

14. Challenge ? How do you know that EM waves can travel in a vacuum? We can see the light from the sun. Light is an EM wave. Space is a vacuum. So if we can see the sunlight the em waves can travel in a vacuum.

15. Connection List 3 ways that light waves are different than sound waves. Sound is slower than light Sound diffracts more than light Sound needs a medium, em waves do not How are light and sound the same? they both transfer energy

16. Challenge Questions You are standing in a pool of water and notice a quarter on the bottom of the pool. Diagram where you would have to stand (show your eye) for the quarter to appear exactly where it actually is. Quarter

17. Connection Why does a pencil placed in a glass of water appear bent? Use words and/or pictures. Light travels at different speeds through different materials. Light travels in straight waves but when one part of the wave hits the water at an angle it slows down before the other part of the waves causing it to bend because light travels faster air than it does in water.