(b) Frequency (4) Measured in Hz
(c) Sound level (5) Decibel
(d) Ultrasonic sound (2) Frequency more than 20,000 Hz
(e) Infrasonic sound (1) Frequency less than 20 Hz
Answer the following questions:
Q: What is periodic motion?
A: Periodic motion is a repetitive back-and-forth movement that occurs at fixed intervals of time.
Q: What is an oscillator?
A: An oscillator is an object that exhibits back-and-forth motion around a central position.
Q: What’s the relationship between intensity and amplitude in sound?
A: The intensity of sound is directly proportional to the square of the amplitude of vibration.
Q: What is the time period of an oscillator?
A: The time period is the time it takes for an oscillator to complete one full oscillation.
Q: What’s the unit for measuring sound level?
A: The unit for measuring sound level is the decibel (dB).
Q: What is ultrasonic sound?
A: Ultrasonic sound is sound with a frequency higher than 20,000 Hz that cannot be heard by humans.
Q: Name one application of ultrasonic sound.
A: One application of ultrasonic sound is cleaning delicate ornaments and small watch parts.
