A tub is filled with water and a wooden cube 10 cm × 10 cm × 10 cm is found in the water.

Question

A tub is filled with water and a wooden cube 10 cm × 10 cm × 10 cm is found in the water. The wooden cube is found to float on the water with a part of it submerged in water. When a metal coin is placed on the wooden cube, the submerged part is increased by 3.87 cm. The mass of the metal coin is ______ gram.

(Take water density as 1 $g / {cm}^{3}$ and density of wood as 0.4 $g / {cm}^{3}$ ) [2026]

Smart Achievers · Accepted Answer

(387)

$Weight of coin = Additional upthrust$

$\Rightarrow m_{c} g = ρ_{l} V_{add} g$

$\Rightarrow m_{c} = 1 \times 3.87 \times {(10)}^{2}$

$\Rightarrow m_{c} = 387 gram$

Solution

Ans.
(387)

$Weight of coin = Additional upthrust$

$\Rightarrow m_{c} g = ρ_{l} V_{add} g$

$\Rightarrow m_{c} = 1 \times 3.87 \times {(10)}^{2}$

$\Rightarrow m_{c} = 387 gram$

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Solution

Ans. (387) Weight of coin=Additional upthrust ⇒mcg=ρlVaddg ⇒mc=1×3.87×(10)2 ⇒mc=387 gram

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Ans.
(387)

$Weight of coin = Additional upthrust$

$\Rightarrow m_{c} g = ρ_{l} V_{add} g$

$\Rightarrow m_{c} = 1 \times 3.87 \times {(10)}^{2}$

$\Rightarrow m_{c} = 387 gram$