Find out how many times they vibrate per second and compare this to the pendulum.
Answers
Explanation:
When a sound is produced, it causes the air molecules to bump into their neighbouring molecules, who then bump into their neighbours, and so on. There is a progression of collisions that pass through the air as a sound wave.
Air itself does not travel with the wave (there is no gush or puff of air that accompanies each sound); each air molecule moves away from a rest point and then, eventually, returns to it.
When we hear something, we are sensing the vibrations in the air. The number of vibrations per second is known as the frequency, measured in Hertz (1 Hz = 1 vibration per second).
These vibrations enter the outer ear and cause the eardrum to vibrate too. We cannot hear the vibrations that are made by waving our hands in the air because they are too slow. The slowest vibration our human ears can hear is 20 times a second. That would be a very low sound.
The fastest vibration we can hear is 20,000 times per second, which would be a very high sound. Animals can hear different frequencies from humans. Cats can hear even higher frequencies than dogs, and porpoises can hear the fastest vibrations of all (up to 150,000 times per second).
The fre- quency of a vibrating pendulum, or of an object on a spring, specifies the num- ber of to-and-fro vibrations it makes in a given time (usually one second). A complete to-and-fro oscillation is one vibration. If it occurs in one second, the frequency is one vibration per second.
Answer:
Explanation:
A 100-Hz wave vibrates 100 times/s. think! The Sears Tower in Chicago sways back and forth at a frequency of about 0.1 Hz.