Question

A metal ball immersed in water weighs $w_{1}$ at $0^\circ C$ and $w_{2}$ at $50^\circ C$ . The coefficient of cubical expansion of metal is less than that of water. Then

• A. $w_{1}>w_{2}$
• B. $w_{1} < w_{2}$
• C. $w_{1}=w_{2}$
• D. data is insufficient

Answer 1

Answer: (B)

As the coefficient of cubical expansion is more for alcohol then metal.
When we increase temperature, expansion in alcohol is more and hence density decreases,
The buoyant force $F=Vρ_{w}g$ decreases as an increase in metal volume are less but the decrease in the density of water is more.
Hence $w_{1} < w_{2}$