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

## 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

## water is 1

the solid displaced 30N of water

45N / 30N = ?

## No fair saying water is 1.

1000 kg/m^3

but not needed because relative requested.

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

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

## Thanks

## To calculate the relative density of an object, you need to know the weight of the object in air and in water. In this case, you have a solid that weighs 45 N in air and 15 N in water.

The relative density (also known as specific gravity) is the ratio of the density of the object to the density of the reference substance, which is usually water. The formula to calculate relative density is:

Relative Density = (Weight in air) / (Weight in air - Weight in water)

Substituting the given values:

Relative Density = 45 N / (45 N - 15 N)

Simplifying the equation:

Relative Density = 45 N / 30 N

Relative Density = 1.5

So, the relative density of the solid is 1.5.