Question

if a body weighs 2.8N in air and 1.3N when immersed completely in water calculate the relative density​

Answer 1

Answer:

The apparent loss of weight of a body is equal to the buoyant force of the liquid on the completely submerged body. Archimedes' principle states that, when a body is partially or completely immersed in a fluid, it experiences an apparent loss in weight that is equal to the weight of the fluid displaced by the immersed part of the body.

The relative density of the body is equal to its weight in air divded by its apparent loss of weight when completely submerged in water, The weight of the object in air is 2.8 N and its apparent loss of weight is 2.8 N - 1.3 N = 1.5 N.

Its relative density is then equal to 2.8 N / 1.5 N. It is numerically equal to 1.87. It is 1.87 times to that of the density of water.