Question

A solid weigh 45N and 15N respectively in air and water. Calculate the relative density

Answer 1

mass = 45/g

change in weight = 45 -15 = 30 N
so
mass of water displaced = 30/g
volume of water displaced = 30/g / water density
which is volume of the solid since it is totally submerged
so
mass of solid / volume of solid
= (45/g) /[(30/g)/water density]
= (45/30)*water density
so
density relative to water = 45/30 = 1.5

Answer 2

water is 1

the solid displaced 30N of water

45N / 30N = ?

Answer 3

No fair saying water is 1.
1000 kg/m^3
but not needed because relative requested.

Answer 4

They should not have said water, just some fluid :)

Answer 5

It is the very good explanation of my question... Thnx...

Answer 6

Thanks