Question

1. what produces the sensation of sound?
2. what is ultrasound?
3. what is an elastic medium? give some examples.
4. anything that imparts a ____ to an elastic medium is a source of ____
5. what are the two subjective qualities of sound?
6. what are the two objective, measureable, qualities of sound?
7. what do air molecules do when a sound is made?
8. what is compression?

9 what is rarefaction?

1. what makes the intensity of the source decrease rapidly?
2. assuming they were the same loudness, a smoke alarm has a ______ pitch than thunder
3. in general, what causes a rise in pitch?

Explanation:

1. Sound is produced by vibrations. When an object vibrates, it causes the surrounding air molecules (or other medium particles) to vibrate, which our ears detect as sound.
2. Ultrasound refers to sound waves with frequencies higher than the upper - limit of human hearing (above 20,000 Hz).
3. An elastic medium is a material that can return to its original shape after being deformed and can transmit mechanical waves. Examples include air, water, and steel.
4. Anything that imparts a vibration to an elastic medium is a source of sound.
5. The two subjective qualities of sound are pitch (related to how high or low a sound seems) and loudness (related to how intense a sound seems).
6. The two objective, measurable qualities of sound are frequency (number of vibrations per second, related to pitch) and amplitude (related to loudness).
7. When a sound is made, air molecules vibrate back and forth in the direction of the sound wave's propagation.
8. Compression is a region in a sound wave where the particles of the medium are closer together than normal.
9. Rarefaction is a region in a sound wave where the particles of the medium are farther apart than normal.
10. The spreading out of sound waves in all directions (spherical spreading) makes the intensity of the source decrease rapidly.
11. Assuming they were the same loudness, a smoke alarm has a higher pitch than thunder.
12. In general, an increase in the frequency of a sound wave causes a rise in pitch.

Answer:

1. Vibrations.
2. Sound waves with frequencies above 20,000 Hz.
3. A material that can return to its original shape after being deformed and transmit mechanical waves; air, water, steel.
4. Vibration; sound.
5. Pitch and loudness.
6. Frequency and amplitude.
7. They vibrate back and forth in the direction of the sound - wave's propagation.
8. A region in a sound wave where the particles of the medium are closer together than normal.
9. A region in a sound wave where the particles of the medium are farther apart than normal.
10. Spherical spreading of sound waves.
11. Higher.
12. An increase in the frequency of a sound wave.