A boy has 60 kg weight. He wants to swim in a river with the help of a wooden log. If relative density of wood is 0.6. What is the minimum volume of wooden log? (Density of river water is 1000 kg / m 3 )

Question

A boy has 60 kg weight. He wants to swim in a river with the help of a wooden log. If relative density of wood is 0.6. What is the minimum volume of wooden log? (Density of river water is 1000 kg / m 3 ) (A)  0.66 m3 (B)  150 m3 (C)  (3/1) m3 (D)  (3/20) m3

Tardigrade Admin · Accepted Answer

From Archimedes principle Weight of (boy + log) = weight of water displaced (60+V × 0.6 × 103)g=V × 103 g ⇒ 0.4 × 103V=60 ⇒ V=(60/0.4 × 103)=(600/400)=(3/20)m3

Q. A boy has $60 k g$ weight. He wants to swim in a river with the help of a wooden log. If relative density of wood is $0.6$ . What is the minimum volume of wooden log?
(Density of river water is $1000 k g / m^{3}$ )

$0.66 m^{3}$

$150 m^{3}$

$\frac{3}{1} m^{3}$

$\frac{3}{20} m^{3}$

From Archimedes principle Weight of (boy + log) = weight of water displaced $(60 + V \times 0.6 \times 1 0^{3}) g = V \times 1 0^{3} g$
$\Rightarrow 0.4 \times 1 0^{3} V = 60$
$\Rightarrow V = \frac{60}{0.4 \times 1 0 ^{3}} = \frac{600}{400} = \frac{3}{20} m^{3}$

Q. A boy has 60kg weight. He wants to swim in a river with the help of a wooden log. If relative density of wood is 0.6. What is the minimum volume of wooden log? (Density of river water is 1000kg/m3 )

0.66m3

150m3

13​m3

203​m3