Question

A wooden block, with a coin placed on its top, floats in water as shown in the figure. The distances $ h $ and $ l $ are shown there. After sometime, the coin falls into the water. Then :

• A. both $ l $ and h increase
• B. both $ l $ and h decrease
• C. $ l $ decreases and h increases
• D. $ l $ increases and h decreases

Answer 1

Answer: (B)

$ l $ will decrease because the block moves up. H will decrease because the coin will displace thevolume $ ({{v}_{1}}) $ of water equal to its own volumewhen it is in water whereas when it is on theblock it will displace the volume of water $ ({{v}_{1}}) $ whose weight is equal to weight of coin andsince density of coin is greater than the density of water $ {{v}_{1}}<{{v}_{2}}. $