Question

A solid block is attached to a spring scale. When the block is suspended in air, the scale reads 20.1 N; when it is completely immersed in water, the scale reads 16.7 N.

A.) What is the volume of the block?

B.) What is the density of the block?

Answer 1

scale reading in air W = 20.1 N
Scale reading in water W ' = 16.7 N
Buoyant force F = W - W '
= 3.4 N
we know F = DVg
from this volume of the block V = F / Dg
where D = density of water = 1000 kg/ m^ 3
= 3.469*10^-4 kg/ m^ 3
(B).relative density = W / ( W-W')
= 5.911
we know relative density = density of block / density of water
fromthis density of the block = relative density * density of
water
= 5911 kg/m^ 3