# Mechanical waves

##### Intros
###### Lessons
1. Mechanical Waves
2. Introduction to periodic waves
3. Velocity
##### Examples
###### Lessons
1. A musical note of frequency 1.8 Hz is sounded on a day when the speed of sound in air is 320 m/s. What is the wavelength of this note in air?
1. A train of waves travel through a rope at the rate of four waves per second. Find the period of the motion.
1. The time taken for one complete cycle of a musical note is 2 × 10-4 s. Find the frequency of the sound.
1. Radio waves are broadcasted at a frequency of120 MHz. Find the period of the electromagnetic waves producing thus type of Radio waves.
1. A person shouts towards a vertical cliff 630m away. The echo of his voice is heard 6.00 s later.
1. What is the speed of sound of the person's voice?
2. The wavelength of the sound is 0.650m. What is its frequency?
3. What is the period of the wave?
1. In order to produce larger wavelength, do you need higher or lower frequency?
1. Five pulses are generated every 0.200s in a pond. What is the speed of propagation of the wave if the wavelength of the surface wave in 2.40cm?
1. A periodic longitudinal wave that has a frequency on 40.0 Hz travels along a coil spring. If the distance between two successive compressions in 0.600m, what is the speed of the water?