Question

A box is made up of iron and it has a volume of 125 cm 3 . Find its mass.
(Density of iron is 7.8 g / cm 3 ).

Answer 1

Answer:

Given that,

Volume of body V=10−4m3

Density of iron, ρi=7800kgm−3

Density of water ρw=1000kgm−3

Weight in air,Wa=ρiVg=7800×10−4×10=7.8N

We know that,

Weight in water = weight in air – buoyancy force

Ww=Wa−ρwVg

Ww=7.8−1000×10−4×10

Ww=6.8N

Hence, the weight of body in water is 6.8 N