Waves that require a medium to travel are called:

The range of audible frequencies for a normal human ear is approximately:

In a transverse wave, particle motion is:

The unit used to measure the loudness of sound is:

The phenomenon of bending of light around obstacles is called:

Echo is caused by the:

Resonance occurs when the frequency of an external force matches the:

The relationship between wave speed, frequency, and wavelength is given by:

The Doppler effect refers to the change in:

The speed of sound is greatest in:

Ultrasonic waves have frequencies: