Waveinteractions fp
- 2. Waves All Around Us Imagine you just spent a day at the beach with your family. You had a blast playing in the ocean, laying out in the sun, listening to music and talking with your family. When you go back to the condo, you heat up some pizza in the microwave and turn on the TV. Can you name all the different waves that were present in your day on the beach?
- 3. Standard S8P4. Students will explore the wave nature of sound and electromagnetic radiation. B. Describe how the behavior of light waves is manipulated causing reflection, diffraction, refraction, and absorption.
- 4. Review From the list of waves you just named, can you identify whether it is electromagnetic or mechanical? What is the difference between electromagnetic waves and mechanical waves? Which one needs a medium? What is a medium? Name 3. Which one causes vibrations?
- 6. Reflection Waves bounce back All waves can be reflected We can see objects because of the visible light waves that are bounced off of them Waves bounces back at the same angle as it hits the object Angle of incidence (original wave) Angle of reflection (bounce back)
- 7. Scattering Scattering A type of reflection Waves collide with matter and reflect in many different directions Blue sky – shortest wave length of visible light scattered by particles in the atmosphere
- 8. Refraction Wave bends as it is transmitted Due to different wave speeds in different mediums gas to solid, gas to liquid Causes optical illusions
- 9. Refraction Rainbow When white light waves separate by refraction, we see colors
- 10. Diffraction Most times waves travel in a straight line Can bend around a barrier Edges of the object are blurry Example – eclipse, x-ray Can bend through an opening Sound waves are much longer than light waves Sound waves bend more
- 11. Absorption Absorption Transfer of energy to an object light to heat light to chemical (by plants with photosynthesis) light to battery to electrical (by solar panels) Soaks up waves Makes waves dimmer – loss of energy
- 12. Interference Overlapping waves Share space Either increases amplitude – constructive The “thump” from the car stereo next to yours. Or, decreases amplitude – destructive You may not hear the person sitting two seats away from you when the cafeteria is crowded.
- 13. Constructive interference happens when waves add up to make a larger amplitude. Suppose you make two wave pulses on a stretched string. One comes from the left and the other comes from the right. When the waves meet, they combine to make a single large pulse.
- 15. Destructive interference What happens when one pulse is on top of the string and the other is on the bottom? When the pulses meet in the middle, they cancel each other out. During destructive interference, waves add up to make a wave with smaller or zero amplitude.