help me with the following problem problem 1 The following densities are given at 20 C: water: 0.998 g / cm ^ 3 iron: 7.86 g / cm ^ 3 aluminum: 2.70 g / cm3. Order the following in order of increasing mass. a) A rectangular iron bar, 81.5 cm x 2.1 cm x 1.6 cm. b) An aluminum sheet, 12.12 m x 3.62 m x 0.003 cm. c) 4,051 L of water