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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?
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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.
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