Question

If a body of mass 2 kg and density 8000 kg m-3 is completely immersed in a
liquid of density 800 kg m-3, calculate the weight of the liquid displaced by it.
(Take g = 10 ms-2)

Answer 1

Here, mass of the body in air, M=2.0kg

density of the body, d=9000kgm3

Density of the liquid, dl=800kgm3

volume of the body, V=Md=2.0kg8000kgm3

Volume of liquid displaced when the body is completely dipped in it = volume of the body =2.5×10−4m3

mass of the liquid displaced, m=Vdl=(2.5×10−4m3)(800kgm3)=0.2kg

weight of the liquid displaced, Wl=mg=(0.2kg)(10ms2)=2N

Force of buoyancy, FB=Wl=2N

2N is the answer