10CAI-Quiz 2

How many nodes and antinodes does a first harmonic have in the closed pipe resonator?

• a. antinodes 4 ,nodes 3

• b. antinodes 3 ,nodes 4

• b. antinodes 2 ,nodes 1

• b. antinodes 1 ,nodes 1

which of the following is the best description for the relationship between the frequency and the length of the closed- pipe ?

• f =nv /4L

• f =nv /4L

• f= 2L/nv

• f = 4L/nv

Which of the following pipes, when hit, would make the highest pitch ? why?

• a. 1 foot long pipe

• b. 2 foot long pipe

• c. 3 foot long pipe

• d. 4 foot long pipe

An air column in a pipe, which is closed at one end, will be in resonance with a vibrating tuning fork with the fundamental frequency 264 Hz, calculate the length of the column is, (Speed of sound = 330 m/s.)

• a. 31.25 cm

• b. 93.75 cm

• c. 200 cm

• d. 150 cm

Long sound waves are...

• high pitched
• low pitched
• medium pitched

What is the Doppler Effect?

• A change in frequency due to the relative motion of a wave source and an observer

• When a wave overlaps with another wave

• When a wave bounces off of another object

• When a wave bends due to traveling through a different medium

An ambulance is driving towards you as you stand on the sidewalk. What happens to the pitch of the siren as it comes towards you?

• It increases

• It decreases

A train is moving towards a sound detector at 31.0m/s blows a 305Hz whistle.what frequency is detected on a stationary train?

• 335 HZ

• 305 Hz

• 234 Hz

• 556 Hz

a beating wave is produced when

• two travelling waves, travelling in the same direction and with the same frequency, superimpose.

• two travelling waves, travelling in the same direction and with the similar frequencies, superimpose

• two travelling waves, travelling in opposite directions and with the same frequency, superimpose.

• two travelling waves travelling in the same direction of the same frequency but of different amplitudes that superimpose

a standing wave in a string of length L (fixed at both ends) is produced when

• two travelling waves, travelling in the same direction and with the same frequency, superimpose.

• two travelling waves, travelling in the same direction and with the similar frequencies, superimpose so long as L = a multiple of λ/2 .

• two travelling waves, travelling in opposite directions and with the same frequency, superimpose.

• two travelling waves, travelling in opposite directions and with the same frequency, superimpose so long as L = a multiple of λ/2