1. -Waves at Boundaries -Reflection -Interference of Waves
Physics
Mrs. Coyle
Coyle, Greece, 2009, Island of Antipaxos

2. How is the speed of a wave affected when a wave enters from one medium to another?
The speed depends on the medium.
It does not depend on frequency and amplitude.
It remains constant in a given medium at the same conditions.
When a wave enters a different medium, its speed changes but its frequency remains the same.

3. Speed of a Wave, v =lf
For a given medium, v=constant.

4. What does a high or low amplitude indicate?
Low Amplitude High Amplitude

5. What happens when a wave reaches a boundary?
Part of the incident wave is transmitted and part of it is reflected.

6. Pulse travelling from less dense to more dense medium.
What happens to the pulse at the interface?

7. Reflection of a Pulse from a Fixed End
What is the
direction of the
reflected
pulse?

8. Reflection of a Wave from a Fixed End: the pulse returns inverted

9. Reflection of a Pulse from a Free End
What is the
direction of the
reflected
pulse?

10. Wave on a String
(Applet)

11. Interference
When two pulses pass the same point at the same time the waves superimpose either constructively or destructively.
Constructive Interference
Destructive Interference

12. Constructive Interference: resulting wave has a greater amplitude.

13. Destructive Interference: Resulting wave has a smaller amplitude.

14. The displacements are added algebraically at the given point in time.

15. Interference

16. Superposition Simulation:
Constructive and Destructive Interference (string with loose or fixed end)

17. One Wave Two Waves Interfering

18. Interference in Water Waves