Properties Of Solids And Liquids Question 233
Question: A streamlined body falls through air from a height hon the surface of a liquid. If d and D(D > d) represents the densities of the material of the body and liquid respectively, then the time after which the body will be instantaneously at rest, is
Options:
A) 9 minute
B) 7 minute
C) 5 minute
D)3 minute
Show Answer
Answer:
Correct Answer: B
Solution:
Time taken to be emptied for h height, $ t=\sqrt{\frac{2h}{g}} $
and for $ \frac{h}{2} $ height, $ t’=\sqrt{\frac{2h/2}{g}}=\sqrt{\frac{h}{g}} $
$ \frac{t’}{t}=\frac{1}{\sqrt{2}}\Rightarrow t’=\frac{t}{\sqrt{2}}=\frac{10}{\sqrt{2}}=7\ minute $
