Question

an object displaces 2.3×〖10〗^(-3) m^3 of water when totally immersed into it. What is the buoyant force exerted by water? What is the density of the object if its mass is 26kg?of what material is the object made of?

Answer 1

I think you mean the object it totally immersed in water, not the other way around. The buoyant force is the weight of the water displaced, which is
(water density)(volume)*g
= 2.3*10^-3 m^3*1.00*10^3 kg/m^3*9.8 m/s^2 = 22.5 Newtons

The density is (26,000 g)/(2.3^10^3) cm^3 = 11.3 g/cm^3

That happens to be the density of the metal lead. There are probably some alloys that have the same density, but they are not commonly used.