Wave Interactions Pre-Assessment

1. Define Reflection The bouncing back of a wave when it meets a surface boundary The bouncing back of a wave when it meets a surface boundary

2. Draw a wave being reflected on a fixed boundary. Direction of movement Direction of movement

3 and 4 Bending of waves as they pass an edge is called diffraction. Draw waves being diffracted around a single obstacle. Obstacle

5. Refraction is the bending of waves when they pass from one medium to another at an angle. Refraction is the bending of waves when they pass from one medium to another at an angle.

6. What type of wave interaction is shown when two or more waves combine? What type of wave interaction is shown when two or more waves combine? Answer: Interference Answer: Interference

7. Draw an example of constructive interference Resulting Wave Original Waves

8. Draw an example of destructive interference. Resulting Original Waves

9. Two different sounds have two different frequencies. Two different sounds have two different frequencies.

10. Explain how you hear beats. Describe in terms of constructive and destructive interferences. Alternating loud and soft sounds cause us to hear beats. The loud sound is heard because of constructive interference. The softer sounds are due to destructive interference. Alternating loud and soft sounds cause us to hear beats. The loud sound is heard because of constructive interference. The softer sounds are due to destructive interference.

11. Standing waves can form when a wave is reflected at the boundary of a medium. In a standing wave, interference of the original wave with the reflected wave causes the medium to vibrate in a stationary pattern that resembles a loop. Standing waves can form when a wave is reflected at the boundary of a medium. In a standing wave, interference of the original wave with the reflected wave causes the medium to vibrate in a stationary pattern that resembles a loop.

12. Draw a standing wave with 5 nodes and 4 antinodes. Label them. NODES Antinodes

# Waves that cause the medium to vibrate parallel to the direction of the wave motion are called longitudinal waves. 16. Waves that cause the medium to vibrate parallel to the direction of the wave motion are called longitudinal waves. 17. Examples: spring moved horizontally 17. Examples: spring moved horizontally 18. Particle motion 18. Particle motion Wave motion

19. Water waves are examples of surface waves. Water waves are examples of surface waves.

20. This type of wave occurs on the boundary between two different mediums. This type of wave occurs on the boundary between two different mediums.

21. The particles in surface waves move both perpendicularly and parallel. The particles in surface waves move both perpendicularly and parallel.*