Three solid samples—aluminium, paraffin wax and iron—are supplied to a school laboratory. Their densities are given as 2.7×103kg m−3, 9.0×102kg m−3 and 7.9×103kg m−3 respectively. The density of water may be taken as 1.0×103kg m−3. Answer the following questions.
(i) State the physical meaning of density.
(ii) Arrange the three solids in increasing order of their densities.
(iii) Which of these solids will float on water? Give a reason for your answer.