Question

an weighs 20g in air and 189 when it is immersed in water . calculate the relative
denisity.
please it's very urgent anybody can solve it fastttt

Answer 1

Relative density = weight in air / (weight in air - weight in water)
RD = 20/(20-18) 
RD = 10.

Answer 2

Relative density can be written as:

$RD = \frac{weight\ in\ air}{weight\ loss\ in\ water} =\frac{weight\ in\ air}{weight\ in\ air-weight\ in\ water}$

weight in air = 20g
weight in water = 18g

$RD = \frac{20}{20-18} = \frac{20}{2} =\boxed{10}$