4.5 Standing Waves

In the diagram which letters represent the nodes

• A B C

• A C E

• B D

• B D E

• A C D

The moving black dot is called:

• a node
• an anti-node
• an anti-amplitude
• the wangy bit

The stationary dot is called:

• a node.
• an anti-node.
• the amplitude.
• the not moving bit.

Which harmonic is shown?

• 1st
• 2nd
• 3rd
• 4th

How many antinodes does this standing wave have?

• 5

• 6

• 7

• 8

Which harmonic is shown?

• 2nd
• 3rd
• 4th
• 5th

An open pipe (1.8 m long) makes a tone travelling at 330 m/s. Calculate its frequency for the 3rd harmonic.

• 183.3 Hz

• 234 Hz

• 275 Hz

• 594 Hz

Standing waves are created by

• Two identical waves reflecting off each other

• Two identical waves being diffracted together

• Two identical waves move through each other in opposite directions

• Two identical waves are diffracted from two identical sources

The first harmonic has

• 1 antinode

• 1 node

• 2 antinodes

• no nodes

The second harmonic on a string fixed at both ends shows

• A wavelength

• Half a wavelength

• Two wavelengths