Buoyancy & Buoyant Force Video Lessons

Concept

# Problem: The average density of the human body is 985 kg/m3, and the typical density of seawater is about 1020 kg/m3.(a) The average density of the human body, after maximum inhalation of air, changes to 945 kg/m3. As a person floating in seawater inhales and exhales slowly, what percentage of his volume moves up out of and down into the water?(b) The Dead Sea (a saltwater lake between Israel and Jordan) is the world's saltiest large body of water. Its average salt content is more than six times that of typical seawater, which explains why there is no plant and animal life in it. Two-thirds of the volume of the body of a person floating in the Dead Sea is observed to be submerged. Determine the density (in kg/m3) of the seawater in the Dead Sea.

###### FREE Expert Solution

At the state of equilibrium, the weight of the body balances the buoyant force.

$\overline{){{\mathbf{F}}}_{{\mathbf{B}}}{\mathbf{=}}{{\mathbf{W}}}_{{\mathbf{h}}}}$

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###### Problem Details

The average density of the human body is 985 kg/m3, and the typical density of seawater is about 1020 kg/m3.

(a) The average density of the human body, after maximum inhalation of air, changes to 945 kg/m3. As a person floating in seawater inhales and exhales slowly, what percentage of his volume moves up out of and down into the water?

(b) The Dead Sea (a saltwater lake between Israel and Jordan) is the world's saltiest large body of water. Its average salt content is more than six times that of typical seawater, which explains why there is no plant and animal life in it. Two-thirds of the volume of the body of a person floating in the Dead Sea is observed to be submerged. Determine the density (in kg/m3) of the seawater in the Dead Sea.