Understanding Sound, Standing Waves, and Harmonics

What is a key feature of a standing wave?

• It has nodes and antinodes.

• It travels in one direction.

• It does not repeat.

• It has a constant amplitude everywhere.

How does a bugle produce different pitches?

• By changing the length of the bugle.

• By using valves.

• By altering the energy of the lips' buzz.

• By pressing keys.

What is required for an open pipe system to resonate?

• A node at one end and an antinode at the other.

• An antinode at both ends.

• A closed end.

• A node at both ends.

In a closed pipe system, what is the configuration at the closed end?

• Neither a node nor an antinode.

• Both a node and an antinode.

• A node.

• An antinode.

What happens to the frequency of a string when its tension is increased?

• The frequency remains the same.

• The frequency increases.

• The frequency decreases.

• The frequency becomes zero.

How can the pitch of a string instrument be changed?

• By changing the color of the string.

• By using a different instrument.

• By altering the length of the string.

• By changing the material of the string.

What is the fundamental frequency of an open pipe that is 2.1 meters long with a speed of sound of 341 m/s?

• 170.5 Hz

• 81.2 Hz

• 162.4 Hz

• 341 Hz

In a closed pipe system, what fraction of a wavelength fits in the first resonant position?

• A quarter of a wavelength

• Three-quarters of a wavelength

• A full wavelength

• Half a wavelength

What is the wavelength of a wave in a string that is 40 cm long and has a wave speed of 250 m/s?

• 0.2 m

• 1.6 m

• 0.8 m

• 0.4 m

How can the pitch of a pipe organ be changed?

• By changing the material of the pipes.

• By using a different type of air.

• By altering the length of the pipes.

• By changing the temperature of the room.