A body is immersed in a liquid of relative density 2.6. It is found that the weight of the body in the liquid is two-thirds of its weight in air. Calculate the density of the body ?

Explanation

Let .p. be the density of the body and `V_1` its volume, then according to Archimedes. principle
`V_1pg-V_1p_1g=2/3V_1pg`
(p1 = density of the liquid)
`therefore V_1pg-V_1pg=2/3V_1pg`
`rArr 3_(P_1)=3xx2.6xx 10^3 kg m^-3`
`7.8xx10^3 kg m^-3`
Density of the body is `7.8xx10^-3 kg m^(-3)`