Question

A solid of density 5000 kg m^-3 weighs 0.5 kgf in air. It is completely immersed in water of density 1000 kg m^-3. Calculate the apparent weight of the solid in water. 

Answer 1

Density of solid = 5000 kg m^-3

Weight of solid = 0.5 kgf

Density of water = 1000 kg m^-3

Here , Upthrust = Volume of the solid × density of water × g

= `(0.5/"g")/5000 xx 1000 xx "g"`

= `0.5/(5000 xx "g") xx 1000 xx "g" = 0.1` kgf

Apparent weight = True weight - Upthrsut 

= 0.5 - 0.1 = 0.4 kgf