Question

A body weighs 450gf in air and 310gf when completely immersed in water.find (1) the volume of the body (2) the loss in weight of the body (3) the upthrust on the body

Answer 1

loss of weight of the body =450gf-310gf=140gf.
according to Archimedes principle the apparent loss of weight =upthrust
so upthrust =140gf.
relative density =weight of an object in air/ loss of weight
                        =450/140
                        =3.21