Describe a simple experiment to determine the speed of sound in air. What approximation is made in the method described by you?

The heart of a man beats 75 times a minute. What is it's (a) frequency and (b) time period?

The separation between two consecutive crests in a transverse wave is 100 m. If wave velocity is 20 m s^-1, find the frequency of wave.

A longitudinal wave travels at a speed of 0.3 m s^-1 and the frequency of a wave is 20 Hz. Find the separation between the two consecutive compressions.