Question

A.

Do you expect an echo to return to you more quickly or less quickly on a hot day, as compared to a cold day?

1. more quickly on a hot day

2. equal times on both days

3. more quickly on a cold day

B.

If you fill your lungs with helium and then try talking, you sound like Donald Duck. What conclusion can you reach about the speed of sound in helium?

1. speed of sound is less in helium

2. speed of sound is the same in helium

3. speed of sound is greater in helium

4. this effect has nothing to do with the speed in helium

C.

You hear a fire truck with a certain intensity, and you are about 1 mile away. Another person hears the same fire truck with an intensity about 10 times less. Roughly, how far is the other person from the fire truck?

1. about the same distance

2. about 3 miles

3. about 10 miles

4. about 30 miles

5. about 100 miles

D.When Minnie talks, she creates a sound level of 60 dB at your location. Mickey talks with the same volume, also giving 60 dB at your location. If both Minnie and Mickey talk simultaneously from the same spot, what would be the new sound level that you hear? (±0.1 dB)

E.Consider an idealized model with a bird emitting constant sound power, with intensity inversely proportional to the square of the distance from the bird. How many decibels does the sound level drop when you move 2.6 times as far away from the bird?

F.

You have a long pipe and a short pipe. Which one has the higher frequency?

1. the long pipe

2. the short pipe

3. both have the same frequency

You blow into an open pipe and produce a tone. What happens to the frequency of the tone if you close the end of the pipe and blow into it again?

1. depends on the speed of sound in the pipe

2. you hear a higher frequency

3. you hear the same frequency

4. you hear a lower frequency

Answer 1