Objective 1

Question 1
Scientists prefer to use mass rather than weight because your weight can sometimes vary as to where you are.    
http://wiki.answers.com/Q/Why_is_mass_more_useful_than_weight_for_measuring_matter

Question 2
The volume = length x width x height : 15.3cm x 9cm x 4.5cm
619.65cm3

Question 3
The unit measurement for density is usually grams or kilograms
http://wiki.answers.com/Q/What_unit_is_used_to_measure_density

Question 4
The formula for finding density is mass/volume
http://wiki.answers.com/Q/What_is_the_formula_to_finding_density

Question 5
The formula for finding volume is length x width x height