1. Expert Analysis: Why do soldiers break step while crossing a suspension bridge?
2. Clinical Logic: A doctor uses a stethoscope to hear heartbeats. Which property of sound is primarily utilized here?
3. Data-based: A SONAR device on a ship sends a signal and receives an echo after $4 \text{ s}$. If the speed of sound in seawater is $1500 \text{ m/s}$, the depth of the ocean is:
4. Experimental Setup: When two tuning forks of slightly different frequencies are sounded together, we hear a periodic rise and fall in loudness called:
5. Which factor determines the "Grave" (low-pitched) or "Shrill" (high-pitched) nature of a musical note?
6. Why does the speed of sound increase on a humid day compared to a dry day?
7. The "Auditory Nerve" in the human ear is responsible for:
8. A boy standing between two parallel cliffs fires a gun. He hears the first echo after $1.5 \text{ s}$ and the second after $2.5 \text{ s}$. The speed of sound is $340 \text{ m/s}$. The distance between the cliffs is:
9. Which property of an ultrasonic wave makes it useful for cleaning small electronic parts?
10. The time period of a simple pendulum depends primarily on its ________.
11. If an object is vibrating at $50,000 \text{ Hz}$, the sound produced is:
12. The sensation of sound persists in the brain for $0.1 \text{ s}$. This is called ________.
13. In a longitudinal wave, the region where particles are closest together is a ________.
14. The loudness of sound is directly proportional to the ________ of the vibration.
15. Why is the sound of a woman generally shriller than that of a man?
16. The "Velocity of sound" in air at $20^\circ\text{C}$ is roughly ________.
17. Noise is produced by ________ vibrations.
18. The speed of sound in solids is ________ than in liquids.
19. Which unit is used to express the wavelength of a sound wave?
20. The reflection of sound from the clouds and land results in ________.
