What is capillarity? What are its uses?
What is CNG? What are its uses?
(a) What is an echo? How is echo formed?
(b) What is the minimum distance in air required from a sound reflecting surface to hear an echo (at 20o C)?
(c) A man standing 825 metres away from a cliff (steep rock) fires a gun. After how long will he hear its echo? The speed of sound in air is 330 m/s.
