Determination of Relative Density of a Solid Substance by Archimedes’ Principle

A body of mass 70 kg, when completely immersed in water, displaces 20,000 cm³ of water. Find: (i) The weight of body in water and (ii) The relative density of material of the body. 

A body of volume V and density ρ is kept completely immersed in a liquid of density ρ_L. If g is the acceleration due to gravity, then write expressions for the following:

(i) The weight of the body, (ii) The upthrust on the body,

(iii) The apparent weight of the body in liquid, (iv) The loss in weight of the body. 

A sphere of iron and another sphere of wood of the same radius are held under water. Compare the upthrust on the two spheres.

[Hint: Both have equal volume inside the water].

A sphere of iron and another of wood, both of same radius are placed on the surface of water. State which of the two will sink? Give a reason for your answer. 

How does the density of material of a body determine whether it will float or sink in water? 

Complete the following sentence.

S.I. unit of density is .......... .