Advertisements
Advertisements
Question
A cork piece is floating on the surface of the water in a pond. A piece of pebble is dropped into the water. What will be your observation?
Advertisements
Solution
As the piece of pebble is dropped into the water, waves are seen to be formed on the surface of the water which travels outwards from the point, where the pebble strikes the water surface. The cork piece simply tosses up and down without any appreciable forward or backward displacement. From this observation, it is concluded that water (medium) does not move, but the wave (or disturbance) advances.
RELATED QUESTIONS
A wave passes from one medium to another medium. Mention one property of the wave out of speed, frequency or wavelength which does not change.
State the use of echo by a bat, dolphin and fisherman.
The following diagram shows three ways in which the string of an instrument can vibrate.
(a) which of the diagram shows the principal note?
(b) which has the frequency four times that of the first?
(c) what is the ratio of the frequency of the vibration in (i) and (ii)?
Write the approximate value of the speed of sound in air.
How are bats able to fly in the dark?
What do you understand by the ‘Echolocation system of Dolphins’?
Why is an echo not heard when the distance between the source of sound and reflection body is less than 10 m?
Explain reflection at the boundary of a rarer medium.
Explain Reflection at curved surfaces.
