NCERT Solutions Curiosity Chapter 4 Activity 4.2: Let us investigate — Sonority

Book page 45 Updated on2026-09-05

Q1.
Take a few objects, such as a metal spoon, a coin, a piece of coal, and a block of wood. Drop them one by one from a certain height. Do you notice any difference in the sound produced by these objects?
Answer

Yes, a clear difference. Drop each object from the same small height on to the same hard floor, and listen carefully.

ObjectMaterialSound producedSonorous?
Metal spoonSteelRingingYes
CoinMetal alloyRingingYes
Piece of coalCarbon (non-metal)Dull thudNo
Block of woodWoodDull thudNo

Conclusion: metals are sonorous; coal and wood are not.

Did you know? A person who cannot see uses exactly this difference. As the white cane taps the ground, a ringing tap means metal — a manhole cover or a grill — and a dull tap means wood or stone. The sound draws the map of the path.
Caution: be careful while dropping the objects, and make sure no one's feet are below.
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