Reflection Superposition Open, Closed End Columns

Question 1

What is reflection?

And give an example of a surface which would reflect sound

Answer 1

Sound waves reflect whenever they encounter a change in density for example a wall.

Question 2

Reflection on a guitar string what happens?

And what degree change in phase occurs?

Answer 2

Reflection on a string there is a 180 degree change in phase

Flipping the reflected wave over so that it interferes constructively with the incident wave.

Question 3

What is a reluctant and incident wave?

Answer 3

Resultant- both incident and reflected wave add to hear a louder sound
Incident- a wave that strikes a boundary where it is either reflected or refracted

Question 4

What is the law of superposition?

Answer 4

Waves occurring at the same time in the same place have an increased effect.

Question 5

What do you do if two waves in a positive phase occur at the same time and point?
Two waves with the opposite phases?
What if they have the same amplitude?

Answer 5

Add their values to calculate their combined effect
Subtract values
The result is nil

Question 6

Open and closed tubes

Many woodwind instruments consist of an ____ enclosed in a hollow _______ tube?

Answer 6

Air column

Hollow metal tube.

Question 7

If the end of the tube is uncovered what can happen and what is it called?

Answer 7

Air in the end of the tube can freely vibrate

Called an “open end”

Question 8

What is it called if both ends of the tube are open or uncovered? Give an example of an instrument like this?

Answer 8

Instrument contains and open end air column

Tuba, trumbone, wind chimes, organ pipes