Take a solid (say a metallic piece). Suspend a solid by a thin thread from the hook of a spring balance. Note it’s weight. Now take a eureka can and fill it with water to it’s spout. Arrange a measuring cylinder below the spout of the eureka can.
Now, immerse the solid gently into water of the eureka can. The water displaced by it gets collected in the measuring cylinder, as shown in figure. When water stops dripping through the spout, note the weight of the solid and the volume of water collected in the measuring cylinder.
As shown in figure, the solid weighs 300 gf in air and 200 gf when it is completely immersed in water. The volume of water collected in the ,measuring cylinder is 100 ml i.e., 100 cm3.
Therefore, loss in weight = 300gf – 200gf = 100gf [Equation 1]
Volume of water displaced = Volume of solid = 100 cm3
Since, density of water = 1 g cm-3
Therefore, weight of water displaced = 100 gf [Equation 2]
From eqns. (i) and (ii)
Weight of water displaced = Upthrust or loss in weight.
Thus, the weight of water displaced by a solid is equal to the loss in weight of the solid. This verifies Archimedes’ principle.
