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प्रश्न
A wooden block with a coin placed on its top, floats in water as shown in figure. The distance l and h are shown in the figure. After some time the coin falls into the water. Then ______.
- l decreases.
- h decreases.
- l increases.
- h increase.
उत्तर
a and b
Explanation:
When the coin falls into the water, the weight of the (block + coin) system decreases, which was balanced by the upthrust force earlier. As the weight of the system decreases. hence upthrust force will also decrease which is only possible when / decreases.
As l decreases, the volume of water displaced by the block decreases, hence h decreases.
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