Question

A body weighs $50$ grams in air and $40$ grams in water. How much would it weigh in a liquid of specific gravity $1.5$ ?

• A. 30 grams
• B. 35 grams
• C. 65 grams
• D. 45 grams

Answer 1

Answer: (B)

$\frac{{\sigma }_L}{{\sigma }_W}=\frac{\text{ upthrust on body in liquid }}{\text{ upthrust on body in water }}$
$\frac{1.5}{1}=\frac{x}{[50-40]g}$
$\Rightarrow x=15g$
$\therefore$ upthrust on body in liquid $=15g$
Weight of the body $=50g$
Hence, body will weigh $(50-15)=35g$ in the liquid.