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Question
Give reasons:
We can easily move our hand in air, but to do the same through a solid block of wood, we need a karate expert.
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Solution
- We can easily move our hand in the air, but to do the same through a solid block of wood, we need a karate expert.
- It is because the molecules of air have less force of attraction between them, and a very small external force can separate them and pass through them.
- However, in solids, the molecules have the maximum force of attraction, and the particles are tightly bound due to this force. Hence, a large amount of external force is required to pass through the solid.
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| Fig. I | Fig. II |
In figure-I, an air column of length ℓ1 is entrapped by a column of Hg of length 8 cm. In figure-II length of same air column at the same temperature is ℓ2. The `ℓ_1/ℓ_2` is:
(1 atm = 76 cm of Hg)
