Explain following terms (1) Periodic time (2) Simple harmonic motion (3) Wave (4) Wavelength (5) Amplitude of a wave (6) Frequency of a wave (7) Wave velocity (8) Audible sound (9) Infrasonic sound (10) Ultrasonic sound (11) Echo (12) Reverberation
GSEB - Class 9 Chapter - 2. Wave Motion and Sound Page 24
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Answer:
1. A time period (denoted by 'T' ) is the time taken for one complete cycle of vibration to pass a given point
2. oscillatory motion under a retarding force proportional to the amount of displacement from an equilibrium position.
3.The disturbance that travelling through a medium or vacuum from one place to other by transferring the energy is called a wave.
4. the distance between successive crests of a wave,
5. The amplitude of a wave refers to the maximum amount of displacement of a particle on the medium from its rest position.
6. Frequency is the number of occurrences of a repeating event per unit of time.
7. Velocity of Wave or Wave Velocity The distance travelled by a wave in one second is called velocity of the wave
8. sound waves with frequency ranging from 20 Hz to 20 KHz is known are audible sound
9. Infrasound, sometimes referred to as low-frequency sound, is sound that is lower in frequency than 20 Hz or cycles per second, the "normal" limit of human hearing.
10. Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing.
11.a sound or sounds caused by the reflection of sound waves from a surface back to the listener.
12. prolongation of a sound; resonance.
Explanation: