Stationary Waves

Question 0

What is an antinode?

Answer 0

A point on a stationary wave with maximum amplitude.

Question 1

What is a node?

Answer 1

A point on a stationary wave that doesn’t move.

Question 2

What is lambda equal to in terms of nodes and antinodes?

Answer 2

Node to node = lambda/2

Node to antinode = lambda/4

Question 3

What is the speed of a stationary wave?

Answer 3

0

Question 4

Microwave stationary wave experiment?

Answer 4

Direct microwave transmitter at metal plate which reflects microwaves back to the source. This sets up a stationary wave. Move probe receiver in between the transmitter and the plate. Areas of high and low intensity represent nodes and antinodes.

Question 5

In the microwave experiment, will there be a node or antinode at the metal sheet?

Answer 5

Node

Question 6

In the microwave experiment, will there be a node or antinode at the transmitter?

Answer 6

Antinode

Question 7

Explain an experiment to show resonance?

Answer 7

Resonance tube:

1) set up open ended cylinder so one end is in water.
2) hit tuning fork on top so air column is forced to vibrate. If stationary wave is formed then fork will make a loud resonance.

Question 8

In the resonance tube experiment where will the node and antinode be if the length of the tube is 1/4wavelength?

Answer 8

Node - water end

Antinode - open end

Question 9

Define fundamental frequency?

Answer 9

The lowest frequency stationary wave for a particular system (like on a guitar string with nodes at both end).

Question 10

How is the note changed in wind instruments?

Answer 10

The length of the air column is changed or the holes in the air column are opened so that different stationary waves are produced.

Question 11

What is a harmonic?

Answer 11

A multiple of the fundamental frequency. For example, the second harmonic has twice as many nodes as antinodes as the fundamental frequency in the same length of vibrator such as a guitar string.

Question 12

How do you work out the wavelengths when given the second and third harmonics?

Answer 12

2nd - lambda = 4L/3

3rd - lambda = 4L/5

Question 13

What is the kundt’s dust tube experiment?

Answer 13

A speaker send sound waves down the inside of a tube, which are reflected at the closed end, therefore creating a stationary wave. The dust vibrates violently at the antinodes and thus ends up in small piles at each node.