Answer:
1. Doppler effect - the apparent change in frequency perceived when the source of sound is approaching or moving away from an observer.
2. Beats- a series of alternating reinforcements and cancellations produced by the interference of waves.
3. Resonance - the vibration of an object at its natural frequency, caused by a force or wave of the same frequency
4. Shock wave - the cone-shaped wave made by a particle moving faster than the speed of a wave in that medium
Step-by-step explanation:
1. Doppler effect refers to the apparent change in the frequency of the source when there is relative motion between the source and the listener. The apparent frequency is greater than source when source and listener approach each other. It is less when source and listener move away from each other.
2. Beats are produced when two slightly different frequency waves interfere. alternate constructive interference and destructive interference produces loud and soft sound.
3. Resonance is the increase in the amplitude of wave when the object vibrates at its natural frequency when it is exposed to a periodic force having frequency very close to the natural un-damped frequency.
4. Shock wave is produced when a body travels at speed greater than the speed of sound in that medium. cone-shaped wave is formed.