Question

A 950-kg cylindrical can buoy floats vertically in seawater. The diameter of the buoy is 0.880 m. Calculate the additional distance the buoy will sink when a 71.0-kg man stands on top of it.

Answer 1

The buoyant force on the buoy is equal to the weight of water it displaces. Seawater has a density of about 1000 kg/m³, depending on which source you consult.take as given in your text book

area of the buoy's ends=r²=*0.44²=0.60821234m²

So imagine the buoy being slowly lowered vertically into water. When one meter of the buoy is submerged, it will have displaced 0.636 cubic meters of saltwater, or 0.60821234 x 1000 kg= 608.2123 kilograms of water.

so when one meter of boyment is dip in sea water buoyant =608.2123*9.8=5960.481N

so for 70 kg men extra vertically distance submurged in water=70*9.8/5960.481=0.11509m=11.509 m