Physics(H) - Standing Waves

Which type of wave is sound?

• Longitudinal

• Transferse

• Torsional

• Surface

Which is the best definition of interference?

• When two sounds are playing they blur together

• When two or more waves are in the same medium, their amplitudes add up

• The frequency of multiple waves get in the way of each other

What is a node?

• A location of constant destructive interference (no movement in the medium)

• A location of constant constructive interference (amplitude oscillation)

• A place where interference is causing particle rotations

A standing wave on a string that is fixed at each end will always have....

• Nodes at each end.

• Antinodes at each end.

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

If a guitar string was vibrating at the fundamental frequency, and the distance from one fixed end to the other fixed end is 0.8m, what is the wavelength of the wave on the string?

• 0.8 m

• 1.6 m

• 0.4 m

Consider a guitar string that is vibrating so that both the fundamental (1st harmonic) and the next overtone (2nd harmonic) are audible. If the fundamental is 120 hz, the 2nd harmonic would be... ?

• 60 hz

• 120 hz

• 240 hz

• 360 hz

Answer explanation

If the wavelength of the 2nd harmonic is 1/2 the wavelength of the fundamental, the frequency of the 2nd harmonic would be 2x the fundamental.

Open pipes have standing waves that have...

• 3 antinodes

• An antinode at each end

• A node at each end

If a pipe is 30 cm long, the fundamental standing wave of air within it would have a wavelength of...

• 15 cm

• 30 cm

• 60 cm

Closed end pipes always have a standing wave that...

• has a node at the closed end and an antinode at the open end

• has two nodes, one at each end

• has two antinodes, one at each end

Fixed - Fixed and Open - Open configurations both have a fundamental that corresponds to _ a wavelength; however, a Closed - Open configuration has a fundamental that corresponds to _ a wavelength.

• 1/2 ... 1/4

• 1 ... 1/2

• 1/2 ... 3/4