Q. The density of ice is $0.9\ gcc^{- 1}$ and that of sea water is$1.1\ gcc^{- 1}$. An ice berg of volume $V$ is floating in sea water. The fraction of ice berg above water level is
A) 1/11
B) 2/11
C) 3/11
D) 4/11
Explanation
(b) Let $v$ be the volume of ice-berg outside the sea water while floating. Therefore, volume of ice-berg inside the sea water$= (V - v)$. As ice-berg is floating, so weight of ice-berg = weight of sea water displaced by ice-berg
$ie\ V \times 0.9 \times g = (V - v) \times 1.1 \times g$
Or $1.1v = 1.1V - 0.9\ V$
Or $v/V = 0.2/1.1 = 2/11$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.