Examples of travelling and standing waves

[Pyroadept]

Homework Statement

Give an example of a traveling wave AND a standing wave for:
1 - Disturbances along a rope
2 - Sound
3 - Light

Homework Equations

None I can think of

The Attempt at a Solution

Hi, could someone please tell me if these are correct and, if not, what could I say instead?

1 String - Travelling - Give one end of the rope a quick jerk up and down.
Standing - Connect a string up to a frequency generator and increase the frequency until resonance occurs in the string - there is now a standing wave in the string.

2 - Sound - Travelling - In an air-filled column with a piston at one end, move the piston back and forth.
Standing - When you play a note on a musical instrument consisting of a pipe closed at one end (e.g. a saxophone), you are creating standing sound waves.

3 - Light - Travelling - The light coming out of a torch.
Standing - Shine two torches at each other.


Thanks

 

[Chewy0087]

Only thing I would say is for light mention something related to coherent & monochromatic;

perhaps a coherent & monochromatic laser at a very high quality mirror or something?

 

[nlightner]

for your submission. Your examples are generally correct, but here are some clarifications and additional information that may be helpful:

1) For the travelling wave on a string, you could also mention the example of a wave propagating along a jump rope when one end is shaken up and down. This is a real-life example that many people can relate to. For the standing wave, you could mention the example of plucking a guitar string and seeing the standing wave patterns on the string.

2) For sound, you could mention that the travelling wave is the sound wave that is produced by any sound source (e.g. a speaker, a person's voice) and travels through the air. For the standing wave, you could mention that it is commonly observed in musical instruments, as you mentioned, but also in some architectural designs such as the whispering gallery in St. Paul's Cathedral.

3) For light, the travelling wave could also be seen in ripples on a water surface or in the waves created when dropping a pebble into a pond. For the standing wave, you could mention the example of a laser beam reflecting back and forth between two parallel mirrors, creating a standing wave of light. This is how some lasers work.

Overall, your examples are good and provide a good understanding of travelling and standing waves in different contexts. Keep up the good work!