In essence, this is the cause, or source, of every sound.
What is something vibrating?
If a sound travels through warm air and then cold air, it will travel faster through this one.
What is the warm air?
Reverberations are echoes of these.
What are echoes?
When you rub a glass causing it to resonate and produce a sound, the pitch will do this if you reduce the amount of water in it.
What is increase?
The "F" in FM radio stands for this.
What is frequency?
A sound wave is this type of wave.
What is longitudinal?
These kinds of frequencies of sound will carry farther in air.
What are low frequency sounds?
In order for a sound to have a refraction it must change this.
What is speed?
The natural frequencey of an object depends on these things.
What are size, shape and elasticity?
The "A" and AM radio stands for this.
What is amplitude?
A sound source producing a low pitched sound is making a sound wave with this type of frequency.
What is a low frequency?
Sounds with this type of wavelength will carry farther in air.
What is long wavelength?
Refraction and reflection of sounds can occur in this kind of medium.
What is any medium that carries sound?
If you strike a tuning fork and hold it against a wooden table, this will happen.
It will get louder and the time it vibrates will decrease.
These kinds of waves can experience wave interference.
What are all kinds of waves?
An object vibrating at 2500 cycles per second will create a wave with this frequency.
What is 2500 hertz?
The speed of sound in the air is the greatest for these types of frequencies.
What is all frequencies.
This causes a refraction of sound over a lake so that the sound bends downward and can be heard clearly across the lake.
What is cold air over the water with a layer of warm air above it?
A piano and a harp both use wires stretched tightly to make sounds, but a piano is louder than a harp because of this.
What is a sounding board?
The phenomenon of beats is a result of this.
What is sound interference?
As the temperature of the air gets colder, the speed of sound traveling through it does this.
What is get slower?
A sound in the air will eventually become this.
What is increased internal energy in the air?
An acoustical engineer designing a music hall must take these three things into account.
What are echoes, reflections and reverberations?
Dolphins make use of these three sound phenomena to detect their surroundings.
What are echoes, the Doppler Effect, and ultrasound?
A piano tuner strikes a tuning fork of 920 Hz. He hits a piano key at the same time and hears 4 beats per second. He slightly loosens the piano string and repeats the process and hears 5 beats per second. The frequency of the piano string is...
What is 915 Hz?