Question

(c) Explain giving reasons:
(i) Water pipes in cold countries often burst in winter.
(ii) Fishes survive in ponds even when the atmospheric temperature is well below 0°C​

Answer 1

Answer:

1. On winter nights, as the atmospheric pressure starts falling below 4°C, water in the pipe lines expand and exert a great pressure on the pipes, causing them to burst.

2. As we know ice is a bad conductor of heat. After sufficient thickness of ice is formed it prevents further loss of heat from the bottom layers of water. This is why fishes and other aquatic animals and plants can survive in ponds and other water bodies even when the atmospheric temperature reaches or is well below 0°.

Answer 2

Answer:

(i) Due to anomalous expansion of water, on winter nights, as the atmospheric pressure starts falling below 4°C, water in the pipe lines expand and exert a great pressure on the pipes, causing them to burst.

ii) Due to anomalous expansion of water, only the top surface of pond freezes. Water below the surface of ice stays between 0°c to 4°c. Thus, fishes can easily survive in ponds even when the atmospheric temperature is well below 0°c.

Explanation:

Hope it helps..❤️