Question

a) Give the mathematical formula for relative density.b) Give the SI unit of density.c) A solid weighs 80 g in air, 64 g in water. Calculate the relative density of solid.URGENT!!!!

Answer 1

1) formula of relative density = density of the substance / density of water. 
2) S.I.unit of density is kg/m³
3) given,
mass of the object in air = 80 grams 
mass of the object in water = 64 grams 
density of water = 1g/cm³
therefore relative density , 
= density of the substance / density of water 
= density of the substance / density in water 
= 80 / 80 - 64 
= 80 / 16
= 5 
therefore relative density = 5
          i hope it helps.......................^_^

Answer 2

a) relative density =density of a substance/density of water    or     w1/w1-w2

b) si unit of density is kg/m³

(c) weight of the solid in air,w1=80g
weight of the solid in water,w2=64g
relative density=w1/w1-w2
=80/80-64
=80/16
=5
relative density of solid =5

hope it helps...