A metal ball immersed in water weighs `w_(1)` at `5^(@)C` and `w_(2) at 50^(@)C`. The coefficient of cubical expansion of metal is less than that of water. Then

Options

A. `w_(1) gt w_(2)`
B. `w_(1) lt w_(2)`
C. `w_(1) = w_(2)`
D. data is insufficient

Answer

B

Explanation

`w_(1) = Mg - F_(B)`
`w_(2) = Mg -F_(B) [(1+gamma_(m)DeltaT)/(1+gamma_(e)DeltaT)] = Mg - F_(B) [1+(gamma_(m)-gamma_(l)) DeltaT]`
Since, `gamma_(m) lt gamma_(l)` So, `w_(2) gt w_(1)`