Question

A hiker shouts toward a vertical cliff 675 m away. The echo is heard 4.00 s later.

(a) What is the speed of sound of the hiker's voice in air? m/s
(b) The wavelength of the sound is 0.774 m. What is its frequency? Hz
(c) What is the period of the wave?

Answer 1

(a) It depends upon the air temperature. Usually about 340 m/s is used for the sound speed.

(b) frequency =
(sound wave speed)/(wavelength)
= 340/0.774
= ___ Hz

(c) Period = 1/(frequency)
(in seconds)

Answer 2

thanks, you were right.